diff --git a/Editor/Mono/AssetStore/AssetStoreContext.cs b/Editor/Mono/AssetStore/AssetStoreContext.cs
index 068e39c522..7669651041 100644
--- a/Editor/Mono/AssetStore/AssetStoreContext.cs
+++ b/Editor/Mono/AssetStore/AssetStoreContext.cs
@@ -12,6 +12,7 @@
 using System.Linq;
 using System.IO;
 using UnityEditor.Web;
+using UnityEditor.Analytics;
 
 namespace UnityEditor
 {
@@ -163,6 +164,15 @@ public void OpenBrowser(string url)
             Application.OpenURL(url);
         }
 
+        [Serializable]
+        public struct DownloadAssetInfo
+        {
+            public string package_id;
+            public string package_name;
+            public string publisher_name;
+            public string category_name;
+        }
+
         public void Download(Package package, DownloadInfo downloadInfo)
         {
             Download(
@@ -205,6 +215,13 @@ public static void Download(string package_id, string url, string key, string pa
             parameters["download"] = download;
 
             AssetStoreUtils.Download(package_id, url, dest, key, parameters.ToString(), resumeOK, doneCallback);
+            EditorAnalytics.SendAssetDownloadEvent(new DownloadAssetInfo()
+            {
+                package_id = package_id,
+                package_name = package_name,
+                publisher_name = publisher_name,
+                category_name = category_name
+            });
         }
 
         /// <summary>
diff --git a/Editor/Mono/Audio/Mixer/GUI/AudioMixerExposedParameterView.cs b/Editor/Mono/Audio/Mixer/GUI/AudioMixerExposedParameterView.cs
index 9832a5c637..8c86a45d7a 100644
--- a/Editor/Mono/Audio/Mixer/GUI/AudioMixerExposedParameterView.cs
+++ b/Editor/Mono/Audio/Mixer/GUI/AudioMixerExposedParameterView.cs
@@ -106,6 +106,10 @@ void DrawElement(Rect rect, int index, bool isActive, bool isFocused)
 
         public Vector2 CalcSize()
         {
+            if (m_ReorderableListWithRenameAndScrollView.list.count != m_Controller.exposedParameters.Length)
+            {
+                RecreateListControl();
+            }
             float maxWidth = 0;
             for (int index = 0; index < m_ReorderableListWithRenameAndScrollView.list.count; index++)
             {
diff --git a/Editor/Mono/Audio/Mixer/GUI/AudioMixerExposedParametersPopup.cs b/Editor/Mono/Audio/Mixer/GUI/AudioMixerExposedParametersPopup.cs
index c2935d9343..b06409045d 100644
--- a/Editor/Mono/Audio/Mixer/GUI/AudioMixerExposedParametersPopup.cs
+++ b/Editor/Mono/Audio/Mixer/GUI/AudioMixerExposedParametersPopup.cs
@@ -18,7 +18,7 @@ internal static void Popup(AudioMixerController controller, GUIStyle style, para
             Rect buttonRect = GUILayoutUtility.GetRect(content, style, options);
             if (EditorGUI.DropdownButton(buttonRect, content, FocusType.Passive, style))
             {
-                PopupWindow.Show(buttonRect, new AudioMixerExposedParametersPopup(controller), null, ShowMode.PopupMenuWithKeyboardFocus);
+                PopupWindow.Show(buttonRect, new AudioMixerExposedParametersPopup(controller));
             }
         }
 
diff --git a/Editor/Mono/BuildPipeline/AssemblyStripper.cs b/Editor/Mono/BuildPipeline/AssemblyStripper.cs
index 69c450511f..3f9223838c 100644
--- a/Editor/Mono/BuildPipeline/AssemblyStripper.cs
+++ b/Editor/Mono/BuildPipeline/AssemblyStripper.cs
@@ -77,7 +77,7 @@ private static bool StripAssembliesTo(string[] assemblies, string[] searchDirs,
             args.AddRange(additionalBlacklist.Select(path => "-x \"" + path + "\""));
 
             args.AddRange(searchDirs.Select(d => "-d \"" + d + "\""));
-            args.AddRange(assemblies.Select(assembly => "-a  \"" + Path.GetFullPath(assembly) + "\""));
+            args.AddRange(assemblies.Select(assembly => "--include-unity-root-assembly=\"" + Path.GetFullPath(assembly) + "\""));
             args.Add($"--dotnetruntime={GetRuntimeArgumentValueForLinker(buildTargetGroup)}");
             args.Add($"--dotnetprofile={GetProfileArgumentValueForLinker(buildTargetGroup)}");
             args.Add("--use-editor-options");
diff --git a/Editor/Mono/Collab/Collab.bindings.cs b/Editor/Mono/Collab/Collab.bindings.cs
index e2755d5759..253f72c7b9 100644
--- a/Editor/Mono/Collab/Collab.bindings.cs
+++ b/Editor/Mono/Collab/Collab.bindings.cs
@@ -206,12 +206,17 @@ public extern void TestClearSoftLockAsCollaborator(string projectGuid, string pr
         [NativeMethod(HasExplicitThis = true, ThrowsException = true, IsThreadSafe = true)]
         extern void SetChangesToPublishInternal(ChangeItem[] changes);
 
+        [NativeMethod(HasExplicitThis = true, ThrowsException = true, IsThreadSafe = true)]
+        extern Change[] GetSelectedChangesInternal();
+
         [NativeMethod(Name = "GetJobProgress", HasExplicitThis = true, ThrowsException = true)]
         extern bool GetJobProgressInternal([Out] ProgressInfo info, int jobId);
 
         [NativeMethod(HasExplicitThis = true, ThrowsException = true)]
         public extern void Publish(string comment, bool useSelectedAssets, bool confirmMatchesPrevious);
 
+        [NativeMethod(HasExplicitThis = true, ThrowsException = true, IsThreadSafe = true)]
+        public extern void ClearSelectedChangesToPublish();
 
         [NativeMethod(HasExplicitThis = true, ThrowsException = true)]
         public extern SoftLock[] GetSoftLocks(string assetGuid);
diff --git a/Editor/Mono/Collab/Collab.cs b/Editor/Mono/Collab/Collab.cs
index 2ab706e9eb..80ec1bd2c5 100644
--- a/Editor/Mono/Collab/Collab.cs
+++ b/Editor/Mono/Collab/Collab.cs
@@ -364,11 +364,17 @@ public bool SetConflictsResolvedTheirs(string[] paths)
 
         public PublishInfo GetChangesToPublish()
         {
-            Change[] changes = GetChangesToPublishInternal();
+            Change[] changes = GetSelectedChangesInternal();
+            bool isFiltered = false;
+            if (Toolbar.isLastShowRequestPartial)
+            {
+                isFiltered = true;
+            }
+
             return new PublishInfo()
             {
                 changes = changes,
-                filter = false
+                filter = isFiltered
             };
         }
 
diff --git a/Editor/Mono/Commands/GOCreationCommands.cs b/Editor/Mono/Commands/GOCreationCommands.cs
index bc37a4b193..17755458d3 100644
--- a/Editor/Mono/Commands/GOCreationCommands.cs
+++ b/Editor/Mono/Commands/GOCreationCommands.cs
@@ -52,7 +52,12 @@ static void CreateEmptyChild(MenuCommand menuCommand)
         {
             var parent = menuCommand.context as GameObject;
             if (parent == null)
-                parent = Selection.activeGameObject;
+            {
+                var activeGO = Selection.activeGameObject;
+                if (activeGO != null && !EditorUtility.IsPersistent(activeGO))
+                    parent = activeGO;
+            }
+
             var go = ObjectFactory.CreateGameObject("GameObject");
             Place(go, parent);
         }
diff --git a/Editor/Mono/ContainerWindow.bindings.cs b/Editor/Mono/ContainerWindow.bindings.cs
index 2c427c9ead..d070126ab3 100644
--- a/Editor/Mono/ContainerWindow.bindings.cs
+++ b/Editor/Mono/ContainerWindow.bindings.cs
@@ -12,7 +12,7 @@ internal enum ShowMode
     {
         // Show as a normal window with max, min & close buttons.
         NormalWindow = 0,
-        // Used for a popup menu and tooltip. On mac this means light shadow and no titlebar.
+        // Used for a popup menu. On mac this means light shadow and no titlebar.
         PopupMenu = 1,
         // Utility window - floats above the app. Disappears when app loses focus.
         Utility = 2,
@@ -22,8 +22,8 @@ internal enum ShowMode
         MainWindow = 4,
         // Aux windows. The ones that close the moment you move the mouse out of them.
         AuxWindow = 5,
-        // Like PopupMenu, but allows keyboard focus (e.g. AddComponentWindow)
-        PopupMenuWithKeyboardFocus = 6
+        // Like PopupMenu, but without keyboard focus
+        Tooltip = 6
     }
 
     //[StaticAccessor("ContainerWindowBindings", StaticAccessorType.DoubleColon)]
diff --git a/Editor/Mono/ContainerWindow.cs b/Editor/Mono/ContainerWindow.cs
index dea9694434..248f7b566c 100644
--- a/Editor/Mono/ContainerWindow.cs
+++ b/Editor/Mono/ContainerWindow.cs
@@ -59,14 +59,24 @@ internal void __internalAwake()
 
         internal static bool IsPopup(ShowMode mode)
         {
-            return (ShowMode.PopupMenu == mode || ShowMode.PopupMenuWithKeyboardFocus == mode);
+            return (ShowMode.PopupMenu == mode);
         }
 
         internal bool isPopup { get { return IsPopup((ShowMode)m_ShowMode); } }
 
         internal void ShowPopup()
         {
-            m_ShowMode = (int)ShowMode.PopupMenu;
+            ShowPopupWithMode(ShowMode.PopupMenu);
+        }
+
+        internal void ShowTooltip()
+        {
+            ShowPopupWithMode(ShowMode.Tooltip);
+        }
+
+        internal void ShowPopupWithMode(ShowMode mode)
+        {
+            m_ShowMode = (int)mode;
             Internal_Show(m_PixelRect, m_ShowMode, m_MinSize, m_MaxSize);
             if (m_RootView)
                 m_RootView.SetWindowRecurse(this);
diff --git a/Editor/Mono/EditorApplication.cs b/Editor/Mono/EditorApplication.cs
index ef237e355f..58680a1ff7 100644
--- a/Editor/Mono/EditorApplication.cs
+++ b/Editor/Mono/EditorApplication.cs
@@ -187,6 +187,9 @@ public static void DirtyHierarchyWindowSorting()
         // Global key up/down event that was not handled by anyone
         internal static CallbackFunction globalEventHandler;
 
+        // Returns true when the pressed keys are defined in the Trigger
+        internal static Func<bool> doPressedKeysTriggerAnyShortcut;
+
         // Windows were reordered
         internal static CallbackFunction windowsReordered;
 
@@ -313,6 +316,14 @@ static void Internal_CallWindowsReordered()
                 windowsReordered();
         }
 
+        [RequiredByNativeCode]
+        static bool DoPressedKeysTriggerAnyShortcutHandler()
+        {
+            if (doPressedKeysTriggerAnyShortcut != null)
+                return doPressedKeysTriggerAnyShortcut();
+            return false;
+        }
+
         [RequiredByNativeCode]
         static void Internal_CallGlobalEventHandler()
         {
diff --git a/Editor/Mono/EditorGUI.cs b/Editor/Mono/EditorGUI.cs
index 6b63726c98..0494d380d8 100644
--- a/Editor/Mono/EditorGUI.cs
+++ b/Editor/Mono/EditorGUI.cs
@@ -18,6 +18,7 @@
 using UnityEditor.Build;
 using UnityEditor.StyleSheets;
 using UnityEngine.Internal;
+using UnityEngine.Rendering;
 using DescriptionAttribute = System.ComponentModel.DescriptionAttribute;
 
 namespace UnityEditor
@@ -1050,6 +1051,7 @@ internal static string DoTextField(RecycledTextEditor editor, int id, Rect posit
                             // Note, OS X send characters for the following keys that we need to eat:
                             // ASCII 25: "End Of Medium" on pressing shift tab
                             // ASCII 27: "Escape" on pressing ESC
+                            nonPrintableTab = true;
                         }
                         else if (editor.IsEditingControl(id))
                         {
@@ -4337,6 +4339,14 @@ private static Color DoColorField(Rect position, int id, Color value, bool showE
                     break;
 
                 case EventType.ExecuteCommand:
+
+                    // Cancel EyeDropper if we change focus.
+                    if (showEyedropper && Event.current.commandName == EventCommandNames.NewKeyboardFocus)
+                    {
+                        EyeDropper.End();
+                        s_ColorPickID = 0;
+                    }
+
                     // when ColorPicker sends an event back to this control's GUIView, it someties retains keyboardControl
                     if (GUIUtility.keyboardControl == id || ColorPicker.originalKeyboardControl == id)
                     {
@@ -5639,11 +5649,11 @@ internal static void ShowRepaints()
         // Draws the alpha channel of a texture within a rectangle.
         internal static void DrawTextureAlphaInternal(Rect position, Texture image, ScaleMode scaleMode, float imageAspect, float mipLevel)
         {
-            DrawPreviewTextureInternal(position, image, alphaMaterial, scaleMode, imageAspect, mipLevel);
+            DrawPreviewTextureInternal(position, image, alphaMaterial, scaleMode, imageAspect, mipLevel, ColorWriteMask.All);
         }
 
         // Draws texture transparently using the alpha channel.
-        internal static void DrawTextureTransparentInternal(Rect position, Texture image, ScaleMode scaleMode, float imageAspect, float mipLevel)
+        internal static void DrawTextureTransparentInternal(Rect position, Texture image, ScaleMode scaleMode, float imageAspect, float mipLevel, ColorWriteMask colorWriteMask)
         {
             if (imageAspect == 0f && image == null)
             {
@@ -5656,7 +5666,7 @@ internal static void DrawTextureTransparentInternal(Rect position, Texture image
 
             DrawTransparencyCheckerTexture(position, scaleMode, imageAspect);
             if (image != null)
-                DrawPreviewTexture(position, image, transparentMaterial, scaleMode, imageAspect, mipLevel);
+                DrawPreviewTexture(position, image, transparentMaterial, scaleMode, imageAspect, mipLevel, colorWriteMask);
         }
 
         internal static void DrawTransparencyCheckerTexture(Rect position, ScaleMode scaleMode, float imageAspect)
@@ -5678,15 +5688,27 @@ internal static void DrawTransparencyCheckerTexture(Rect position, ScaleMode sca
         }
 
         // Draws the texture within a rectangle.
-        internal static void DrawPreviewTextureInternal(Rect position, Texture image, Material mat, ScaleMode scaleMode, float imageAspect, float mipLevel)
+        internal static void DrawPreviewTextureInternal(Rect position, Texture image, Material mat, ScaleMode scaleMode, float imageAspect, float mipLevel, ColorWriteMask colorWriteMask)
         {
             if (Event.current.type == EventType.Repaint)
             {
                 if (imageAspect == 0)
                     imageAspect = image.width / (float)image.height;
 
+                Color colorMask = new Color(1, 1, 1, 1);
+
+                if ((colorWriteMask & ColorWriteMask.Red) == 0)
+                    colorMask.r = 0;
+                if ((colorWriteMask & ColorWriteMask.Green) == 0)
+                    colorMask.g = 0;
+                if ((colorWriteMask & ColorWriteMask.Blue) == 0)
+                    colorMask.b = 0;
+                if ((colorWriteMask & ColorWriteMask.Alpha) == 0)
+                    colorMask.a = 0;
+
                 if (mat == null)
                     mat = GetMaterialForSpecialTexture(image, colorMaterial);
+                mat.SetColor("_ColorMask", colorMask);
                 mat.SetFloat("_Mip", mipLevel);
 
                 RenderTexture rt = image as RenderTexture;
@@ -6343,9 +6365,9 @@ public static void DrawTextureAlpha(Rect position, Texture image, ScaleMode scal
         }
 
         // Draws texture transparently using the alpha channel.
-        public static void DrawTextureTransparent(Rect position, Texture image, [DefaultValue("ScaleMode.StretchToFill")] ScaleMode scaleMode, [DefaultValue("0")] float imageAspect, [DefaultValue("-1")] float mipLevel)
+        public static void DrawTextureTransparent(Rect position, Texture image, [DefaultValue("ScaleMode.StretchToFill")] ScaleMode scaleMode, [DefaultValue("0")] float imageAspect, [DefaultValue("-1")] float mipLevel, [DefaultValue("ColorWriteMask.All")] ColorWriteMask colorWriteMask)
         {
-            DrawTextureTransparentInternal(position, image, scaleMode, imageAspect, mipLevel);
+            DrawTextureTransparentInternal(position, image, scaleMode, imageAspect, mipLevel, colorWriteMask);
         }
 
         [ExcludeFromDocs]
@@ -6360,16 +6382,35 @@ public static void DrawTextureTransparent(Rect position, Texture image)
             DrawTextureTransparent(position, image, ScaleMode.StretchToFill, 0);
         }
 
+        [ExcludeFromDocs]
         public static void DrawTextureTransparent(Rect position, Texture image, ScaleMode scaleMode, float imageAspect)
         {
-            DrawTextureTransparentInternal(position, image, scaleMode, imageAspect, -1);
+            DrawTextureTransparent(position, image, scaleMode, imageAspect, -1);
+        }
+
+        [ExcludeFromDocs]
+        public static void DrawTextureTransparent(Rect position, Texture image, ScaleMode scaleMode, float imageAspect, float mipLevel)
+        {
+            DrawTextureTransparent(position, image, scaleMode, imageAspect, mipLevel, ColorWriteMask.All);
         }
 
         // Draws the texture within a rectangle.
         public static void DrawPreviewTexture(Rect position, Texture image, [DefaultValue("null")] Material mat, [DefaultValue("ScaleMode.StretchToFill")] ScaleMode scaleMode,
-            [DefaultValue("0")] float imageAspect, [DefaultValue("-1")] float mipLevel)
+            [DefaultValue("0")] float imageAspect, [DefaultValue("-1")] float mipLevel, [DefaultValue("ColorWriteMask.All")] ColorWriteMask colorWriteMask)
         {
-            DrawPreviewTextureInternal(position, image, mat, scaleMode, imageAspect, mipLevel);
+            DrawPreviewTextureInternal(position, image, mat, scaleMode, imageAspect, mipLevel, colorWriteMask);
+        }
+
+        [ExcludeFromDocs]
+        public static void DrawPreviewTexture(Rect position, Texture image, Material mat, ScaleMode scaleMode, float imageAspect, float mipLevel)
+        {
+            DrawPreviewTexture(position, image, mat, scaleMode, imageAspect, mipLevel, ColorWriteMask.All);
+        }
+
+        [ExcludeFromDocs]
+        public static void DrawPreviewTexture(Rect position, Texture image, Material mat, ScaleMode scaleMode, float imageAspect)
+        {
+            DrawPreviewTexture(position, image, mat, scaleMode, imageAspect, -1);
         }
 
         [ExcludeFromDocs]
@@ -6390,12 +6431,6 @@ public static void DrawPreviewTexture(Rect position, Texture image)
             DrawPreviewTexture(position, image, null, ScaleMode.StretchToFill, 0);
         }
 
-        [ExcludeFromDocs]
-        public static void DrawPreviewTexture(Rect position, Texture image, Material mat, ScaleMode scaleMode, float imageAspect)
-        {
-            DrawPreviewTextureInternal(position, image, mat, scaleMode, imageAspect, -1);
-        }
-
         [ExcludeFromDocs]
         public static void LabelField(Rect position, string label)
         {
diff --git a/Editor/Mono/EditorHandles/BoundsHandle/PrimitiveBoundsHandle.cs b/Editor/Mono/EditorHandles/BoundsHandle/PrimitiveBoundsHandle.cs
index f10253d950..7f9efafb9a 100644
--- a/Editor/Mono/EditorHandles/BoundsHandle/PrimitiveBoundsHandle.cs
+++ b/Editor/Mono/EditorHandles/BoundsHandle/PrimitiveBoundsHandle.cs
@@ -122,8 +122,8 @@ public void DrawHandle()
 
             // handles
             int prevHotControl = GUIUtility.hotControl;
-            Vector3 cameraLocalPos = Handles.inverseMatrix.MultiplyPoint(Camera.current.transform.position);
-            bool isCameraInsideBox = m_Bounds.Contains(cameraLocalPos);
+            bool isCameraInsideBox = Camera.current != null
+                && m_Bounds.Contains(Handles.inverseMatrix.MultiplyPoint(Camera.current.transform.position));
             EditorGUI.BeginChangeCheck();
             using (new Handles.DrawingScope(Handles.color * handleColor))
                 MidpointHandles(ref minPos, ref maxPos, isCameraInsideBox);
diff --git a/Editor/Mono/EditorHandles/JointAngularLimitHandle.cs b/Editor/Mono/EditorHandles/JointAngularLimitHandle.cs
index 10c838a157..9bbe0c21c8 100644
--- a/Editor/Mono/EditorHandles/JointAngularLimitHandle.cs
+++ b/Editor/Mono/EditorHandles/JointAngularLimitHandle.cs
@@ -26,10 +26,12 @@ private static float GetSortingDistance(ArcHandle handle)
             Vector3 worldPosition = Handles.matrix.MultiplyPoint3x4(
                 Quaternion.AngleAxis(handle.angle, Vector3.up) * Vector3.forward * handle.radius
             );
-            Vector3 toHandle = worldPosition - Camera.current.transform.position;
-            if (Camera.current.orthographic)
+            Vector3 toHandle = Camera.current == null
+                ? worldPosition
+                : worldPosition - Camera.current.transform.position;
+            if (Camera.current == null || Camera.current.orthographic)
             {
-                Vector3 lookVector = Camera.current.transform.forward;
+                Vector3 lookVector = Camera.current == null ? Vector3.forward : Camera.current.transform.forward;
                 toHandle = lookVector * Vector3.Dot(lookVector, toHandle);
             }
             return toHandle.sqrMagnitude;
diff --git a/Editor/Mono/EditorUserBuildSettings.bindings.cs b/Editor/Mono/EditorUserBuildSettings.bindings.cs
index 04b6e3a25a..f7bddf49a9 100644
--- a/Editor/Mono/EditorUserBuildSettings.bindings.cs
+++ b/Editor/Mono/EditorUserBuildSettings.bindings.cs
@@ -626,6 +626,15 @@ public static extern bool switchNVNShaderDebugging
             set;
         }
 
+        // Enable debug validation of NVN drawcalls
+        public static extern bool switchNVNDrawValidation
+        {
+            [NativeMethod("GetNVNDrawValidation")]
+            get;
+            [NativeMethod("SetNVNDrawValidation")]
+            set;
+        }
+
         // Enable linkage of the Heap inspector tool for Nintendo Switch.
         public static extern bool switchEnableHeapInspector
         {
diff --git a/Editor/Mono/EditorUtility.cs b/Editor/Mono/EditorUtility.cs
index b197a5a8c8..5ebdd84813 100644
--- a/Editor/Mono/EditorUtility.cs
+++ b/Editor/Mono/EditorUtility.cs
@@ -198,25 +198,25 @@ public static Object InstantiatePrefab(Object target)
             return PrefabUtility.InstantiatePrefab(target);
         }
 
-        [Obsolete("Use PrefabUtility.ReplacePrefab", false)]
+        [Obsolete("Use PrefabUtility.SaveAsPrefabAsset with a path instead.", false)]
         public static GameObject ReplacePrefab(GameObject go, Object targetPrefab, ReplacePrefabOptions options)
         {
             return PrefabUtility.ReplacePrefab(go, targetPrefab, options);
         }
 
-        [Obsolete("Use PrefabUtility.ReplacePrefab", false)]
+        [Obsolete("Use PrefabUtility.SaveAsPrefabAsset or PrefabUtility.SaveAsPrefabAssetAndConnect with a path instead.", false)]
         public static GameObject ReplacePrefab(GameObject go, Object targetPrefab)
         {
             return PrefabUtility.ReplacePrefab(go, targetPrefab, ReplacePrefabOptions.Default);
         }
 
-        [Obsolete("Use PrefabUtility.CreateEmptyPrefab", false)]
+        [Obsolete("The concept of creating a completely empty Prefab has been discontinued. You can however use PrefabUtility.SaveAsPrefabAsset with an empty GameObject.", false)]
         public static Object CreateEmptyPrefab(string path)
         {
             return PrefabUtility.CreateEmptyPrefab(path);
         }
 
-        [Obsolete("Use PrefabUtility.RevertPrefabInstance", false)]
+        [Obsolete("Use PrefabUtility.RevertPrefabInstance.", false)]
         public static bool ReconnectToLastPrefab(GameObject go)
         {
             return PrefabUtility.ReconnectToLastPrefab(go);
@@ -240,7 +240,7 @@ public static GameObject FindPrefabRoot(GameObject source)
             return PrefabUtility.FindPrefabRoot(source);
         }
 
-        [Obsolete("Use PrefabUtility.ResetToPrefabState", false)]
+        [Obsolete("Use PrefabUtility.RevertObjectOverride.", false)]
         public static bool ResetToPrefabState(Object source)
         {
             return PrefabUtility.ResetToPrefabState(source);
diff --git a/Editor/Mono/EditorWindow.cs b/Editor/Mono/EditorWindow.cs
index 1b17962e0f..00590ec4be 100644
--- a/Editor/Mono/EditorWindow.cs
+++ b/Editor/Mono/EditorWindow.cs
@@ -478,8 +478,18 @@ public void ShowUtility()
             ShowWithMode(ShowMode.Utility);
         }
 
-        // Used for popup style windows.
+        internal void ShowTooltip()
+        {
+            ShowPopupWithMode(ShowMode.Tooltip);
+        }
+
         public void ShowPopup()
+        {
+            ShowPopupWithMode(ShowMode.PopupMenu);
+        }
+
+        // Used for popup style windows.
+        internal void ShowPopupWithMode(ShowMode mode)
         {
             if (m_Parent == null)
             {
@@ -494,7 +504,7 @@ public void ShowPopup()
                 cw.position = r;
                 cw.rootView = host;
                 MakeParentsSettingsMatchMe();
-                cw.ShowPopup();
+                cw.ShowPopupWithMode(mode);
             }
         }
 
@@ -531,7 +541,7 @@ public void ShowAsDropDown(Rect buttonRect, Vector2 windowSize)
 
         internal void ShowAsDropDown(Rect buttonRect, Vector2 windowSize, PopupLocation[] locationPriorityOrder)
         {
-            ShowAsDropDown(buttonRect, windowSize, locationPriorityOrder, ShowMode.PopupMenuWithKeyboardFocus);
+            ShowAsDropDown(buttonRect, windowSize, locationPriorityOrder, ShowMode.PopupMenu);
         }
 
         internal void ShowAsDropDown(Rect buttonRect, Vector2 windowSize, PopupLocation[] locationPriorityOrder, ShowMode mode)
@@ -550,9 +560,9 @@ internal void ShowAsDropDown(Rect buttonRect, Vector2 windowSize, PopupLocation[
             position = ShowAsDropDownFitToScreen(buttonRect, windowSize, locationPriorityOrder);
 
             // ShowWithMode() always grabs window focus so we use ShowPopup() for popup windows so PopupWindowWithoutFocus
-            // will work correctly (no focus when opened)
-            if (ContainerWindow.IsPopup(mode) && mode != ShowMode.PopupMenuWithKeyboardFocus)
-                ShowPopup();
+            // will work correctly (no focus when opened).
+            if (ContainerWindow.IsPopup(mode))
+                ShowPopupWithMode(mode);
             else
                 ShowWithMode(mode);
 
diff --git a/Editor/Mono/GI/LightmapEditorSettings.bindings.cs b/Editor/Mono/GI/LightmapEditorSettings.bindings.cs
index 4f841a6632..2a28803785 100644
--- a/Editor/Mono/GI/LightmapEditorSettings.bindings.cs
+++ b/Editor/Mono/GI/LightmapEditorSettings.bindings.cs
@@ -29,8 +29,11 @@ public enum Lightmapper
             [Obsolete("Use Lightmapper.ProgressiveCPU instead. (UnityUpgradable) -> UnityEditor.LightmapEditorSettings/Lightmapper.ProgressiveCPU", true)]
             PathTracer = 1,
 
-            // Lightmaps are baked by the Progressive lightmapper (Wintermute + OpenRL based).
-            ProgressiveCPU = 1
+            // Lightmaps are baked by the CPU Progressive lightmapper (Wintermute + OpenRL based).
+            ProgressiveCPU = 1,
+
+            // Lightmaps are baked by the GPU Progressive lightmapper (RadeonRays + OpenCL based).
+            ProgressiveGPU = 2
         }
 
         // Which path tracer sampling scheme is used.
diff --git a/Editor/Mono/GUI/ColorPicker.cs b/Editor/Mono/GUI/ColorPicker.cs
index 453514fc52..d2ef8314f7 100644
--- a/Editor/Mono/GUI/ColorPicker.cs
+++ b/Editor/Mono/GUI/ColorPicker.cs
@@ -570,7 +570,7 @@ void DoColorSwatchAndEyedropper()
             if (GUILayout.Button(Styles.eyeDropper, GUIStyle.none, GUILayout.Width(40), GUILayout.ExpandWidth(false)))
             {
                 GUIUtility.keyboardControl = 0;
-                EyeDropper.Start(m_Parent, false);
+                EyeDropper.Start(m_Parent);
                 m_ColorBoxMode = ColorBoxMode.EyeDropper;
                 GUIUtility.ExitGUI();
             }
@@ -958,6 +958,15 @@ void OnGUI()
                 }
             }
 
+            // Cancel EyeDropper if we change focus.
+            if (m_ColorBoxMode == ColorBoxMode.EyeDropper &&
+                Event.current.type == EventType.ExecuteCommand &&
+                Event.current.commandName == EventCommandNames.NewKeyboardFocus)
+            {
+                EyeDropper.End();
+                OnEyedropperCancelled();
+            }
+
             // Remove keyfocus when clicked outside any control
             if ((Event.current.type == EventType.MouseDown && Event.current.button != 1) || Event.current.type == EventType.ContextClick)
             {
@@ -1229,17 +1238,17 @@ internal class EyeDropper : GUIView
         private bool m_Focused = false;
         private Action<Color> m_ColorPickedCallback;
 
-        public static void Start(GUIView viewToUpdate, bool stealFocus = true)
+        public static void Start(GUIView viewToUpdate)
         {
-            Start(viewToUpdate, null, stealFocus);
+            Start(viewToUpdate, null);
         }
 
-        public static void Start(Action<Color> colorPickedCallback, bool stealFocus = true)
+        public static void Start(Action<Color> colorPickedCallback)
         {
-            Start(null, colorPickedCallback, stealFocus);
+            Start(null, colorPickedCallback);
         }
 
-        static void Start(GUIView viewToUpdate, Action<Color> colorPickedCallback, bool stealFocus)
+        static void Start(GUIView viewToUpdate, Action<Color> colorPickedCallback)
         {
             instance.m_DelegateView = viewToUpdate;
             instance.m_ColorPickedCallback = colorPickedCallback;
@@ -1255,8 +1264,6 @@ static void Start(GUIView viewToUpdate, Action<Color> colorPickedCallback, bool
             win.position = new Rect(-kDummyWindowSize / 2, -kDummyWindowSize / 2, kDummyWindowSize, kDummyWindowSize);
             instance.wantsMouseMove = true;
             instance.StealMouseCapture();
-            if (stealFocus)
-                instance.Focus();
         }
 
         public static void End()
diff --git a/Editor/Mono/GUI/FlexibleMenu/FlexibleMenu.cs b/Editor/Mono/GUI/FlexibleMenu/FlexibleMenu.cs
index b060fcdea7..8cdfc53eb2 100644
--- a/Editor/Mono/GUI/FlexibleMenu/FlexibleMenu.cs
+++ b/Editor/Mono/GUI/FlexibleMenu/FlexibleMenu.cs
@@ -243,7 +243,7 @@ void CreateNewItemButton(Rect itemRect)
                         SelectItem(newIndex);
                         EditorApplication.RequestRepaintAllViews(); // We want to repaint the flexible menu (currently in modifyItemUI)
                     });
-                PopupWindow.Show(plusRect, m_ModifyItemUI, null, ShowMode.PopupMenuWithKeyboardFocus);
+                PopupWindow.Show(plusRect, m_ModifyItemUI);
             }
         }
 
@@ -261,7 +261,7 @@ void EditExistingItem(Rect itemRect, int index)
                     m_ItemProvider.Replace(index, obj);
                     EditorApplication.RequestRepaintAllViews(); // We want to repaint the flexible menu (currently in modifyItemUI)
                 });
-            PopupWindow.Show(itemRect, m_ModifyItemUI, null, ShowMode.PopupMenuWithKeyboardFocus);
+            PopupWindow.Show(itemRect, m_ModifyItemUI);
         }
 
         void DeleteItem(int index)
diff --git a/Editor/Mono/GUI/Toolbar.cs b/Editor/Mono/GUI/Toolbar.cs
index 22e979d006..12cebecd4d 100644
--- a/Editor/Mono/GUI/Toolbar.cs
+++ b/Editor/Mono/GUI/Toolbar.cs
@@ -137,6 +137,7 @@ protected override void OnDisable()
 
         public static Toolbar get = null;
         public static bool requestShowCollabToolbar = false;
+        public static bool isLastShowRequestPartial = true;
 
         internal static string lastLoadedLayoutName
         {
diff --git a/Editor/Mono/GUI/TreeView/GameObjectTreeViewDataSource.cs b/Editor/Mono/GUI/TreeView/GameObjectTreeViewDataSource.cs
index 26f2ba9e37..1182c65d9d 100644
--- a/Editor/Mono/GUI/TreeView/GameObjectTreeViewDataSource.cs
+++ b/Editor/Mono/GUI/TreeView/GameObjectTreeViewDataSource.cs
@@ -208,10 +208,6 @@ void CreateRootItem(HierarchyProperty property)
                 // All game objects
                 m_RootItem = new GameObjectTreeViewItem(m_RootInstanceID, rootDepth, null, "RootOfAll");
             }
-
-            // Ensure root is expanded if not shown
-            if (!showRootItem)
-                SetExpanded(m_RootItem, true);
         }
 
         void ClearSearchFilter()
diff --git a/Editor/Mono/GUI/WindowLayout.cs b/Editor/Mono/GUI/WindowLayout.cs
index 7ce55f3e21..047ce599c4 100644
--- a/Editor/Mono/GUI/WindowLayout.cs
+++ b/Editor/Mono/GUI/WindowLayout.cs
@@ -356,10 +356,13 @@ internal static void MaximizeKeyHandler(ShortcutArguments args)
 
             var mouseOverWindow = EditorWindow.mouseOverWindow;
 
-            if (IsMaximized(mouseOverWindow))
-                Unmaximize(mouseOverWindow);
-            else
-                Maximize(mouseOverWindow);
+            if (mouseOverWindow != null)
+            {
+                if (IsMaximized(mouseOverWindow))
+                    Unmaximize(mouseOverWindow);
+                else
+                    Maximize(mouseOverWindow);
+            }
         }
 
         public static void AddSplitViewAndChildrenRecurse(View splitview, ArrayList list)
diff --git a/Editor/Mono/GameView/GameViewSizes.cs b/Editor/Mono/GameView/GameViewSizes.cs
index 6a326192d2..72b896eda3 100644
--- a/Editor/Mono/GameView/GameViewSizes.cs
+++ b/Editor/Mono/GameView/GameViewSizes.cs
@@ -239,9 +239,10 @@ private void InitBuiltinGroups()
                 k_4_3_Landscape, k_4_3_Portrait,
                 k_iPhone4_Portrait, k_iPhone4_Landscape,
                 k_iPhone5_Portrait, k_iPhone5_Landscape,
-                k_iPad_768p_Landscape, k_iPad_768p_Portrait);
+                k_iPad_768p_Landscape, k_iPad_768p_Portrait,
+                m_Remote);
 
-            m_Android.AddBuiltinSizes(kFree, m_Remote,
+            m_Android.AddBuiltinSizes(kFree,
                 k_800x480_Portrait, k_800x480_Landscape,
                 k_720p_Portrait, k_720p_Landscape,
                 k_1080p_Portrait, k_1080p_Landscape,
@@ -249,7 +250,8 @@ private void InitBuiltinGroups()
                 k_2560x1440_Portrait, k_2560x1440_Landscape,
                 k_2960x1440_Portrait, k_2960x1440_Landscape,
                 k_16_9_Portrait, k_16_9_Landscape,
-                k_18_9_Portrait, k_18_9_Landscape);
+                k_18_9_Portrait, k_18_9_Landscape,
+                m_Remote);
 
             m_HMD.AddBuiltinSizes(kFree, m_Remote);
         }
diff --git a/Editor/Mono/HandleUtility.cs b/Editor/Mono/HandleUtility.cs
index 8fc8f52881..2e87d2449c 100644
--- a/Editor/Mono/HandleUtility.cs
+++ b/Editor/Mono/HandleUtility.cs
@@ -26,7 +26,7 @@ public static float CalcLineTranslation(Vector2 src, Vector2 dest, Vector3 srcPo
             // The constrained direction is facing towards the camera, THATS BAD when the handle is close to the camera
             // The srcPosition  goes through to the other side of the camera
             float invert = 1.0F;
-            Vector3 cameraForward = Camera.current.transform.forward;
+            Vector3 cameraForward = Camera.current == null ? Vector3.forward : Camera.current.transform.forward;
             if (Vector3.Dot(constraintDir, cameraForward) < 0.0F)
                 invert = -1.0F;
 
@@ -36,8 +36,13 @@ public static float CalcLineTranslation(Vector2 src, Vector2 dest, Vector3 srcPo
             Vector3 cd = constraintDir;
             cd.y = -cd.y;
             Camera cam = Camera.current;
-            Vector2 p1 = EditorGUIUtility.PixelsToPoints(cam.WorldToScreenPoint(srcPosition));
-            Vector2 p2 = EditorGUIUtility.PixelsToPoints(cam.WorldToScreenPoint(srcPosition + constraintDir * invert));
+            // if camera is null, then we are drawing in OnGUI, where y-coordinate goes top-to-bottom
+            Vector2 p1 = cam == null
+                ? Vector2.Scale(srcPosition, new Vector2(1f, -1f))
+                : EditorGUIUtility.PixelsToPoints(cam.WorldToScreenPoint(srcPosition));
+            Vector2 p2 = cam == null
+                ? Vector2.Scale(srcPosition + constraintDir * invert, new Vector2(1f, -1f))
+                : EditorGUIUtility.PixelsToPoints(cam.WorldToScreenPoint(srcPosition + constraintDir * invert));
             Vector2 p3 = dest;
             Vector2 p4 = src;
 
diff --git a/Editor/Mono/Handles.cs b/Editor/Mono/Handles.cs
index 4dd97995b5..db89421be6 100644
--- a/Editor/Mono/Handles.cs
+++ b/Editor/Mono/Handles.cs
@@ -550,8 +550,8 @@ public static void DotHandleCap(int controlID, Vector3 position, Quaternion rota
                     // Only apply matrix to the position because DotCap is camera facing
                     position = matrix.MultiplyPoint(position);
 
-                    Vector3 sideways = Camera.current.transform.right * size;
-                    Vector3 up = Camera.current.transform.up * size;
+                    Vector3 sideways = (Camera.current == null ? Vector3.right : Camera.current.transform.right) * size;
+                    Vector3 up = (Camera.current == null ? Vector3.up : Camera.current.transform.up) * size;
 
                     Color col = color * new Color(1, 1, 1, 0.99f);
                     HandleUtility.ApplyWireMaterial(Handles.zTest);
diff --git a/Editor/Mono/Inspector/Avatar/AvatarMappingEditor.cs b/Editor/Mono/Inspector/Avatar/AvatarMappingEditor.cs
index 50ceac4111..9cf9bfb61a 100644
--- a/Editor/Mono/Inspector/Avatar/AvatarMappingEditor.cs
+++ b/Editor/Mono/Inspector/Avatar/AvatarMappingEditor.cs
@@ -251,15 +251,27 @@ private void HandleBodyView(int bodyView)
 
         Vector2 m_FoldoutScroll = Vector2.zero;
 
-        public override void OnInspectorGUI()
+        private void SetupInternalProperties()
+        {
+            m_HumanBoneArray = serializedObject.FindProperty("m_HumanDescription.m_Human");
+            m_Skeleton = serializedObject.FindProperty("m_HumanDescription.m_Skeleton");
+        }
+
+        private void HandleUndoPerformed()
         {
             if (Event.current.type == EventType.ValidateCommand && Event.current.commandName == EventCommandNames.UndoRedoPerformed)
             {
+                SetupInternalProperties();
+
                 AvatarSetupTool.TransferPoseToDescription(m_Skeleton, root);
                 for (int i = 0; i < m_Bones.Length; i++)
                     m_Bones[i].Serialize(m_HumanBoneArray);
             }
+        }
 
+        public override void OnInspectorGUI()
+        {
+            HandleUndoPerformed();
             UpdateSelectedBone();
 
             // case 837655.  GUI.keyboardControl is overriden when changing scene selection.
diff --git a/Editor/Mono/Inspector/CameraEditor.cs b/Editor/Mono/Inspector/CameraEditor.cs
index 1cd244ae15..81e164090d 100644
--- a/Editor/Mono/Inspector/CameraEditor.cs
+++ b/Editor/Mono/Inspector/CameraEditor.cs
@@ -213,7 +213,7 @@ public void DrawProjection()
                         GUIContent content = EditorGUI.BeginProperty(EditorGUILayout.BeginHorizontal(), Styles.fieldOfView, fieldOfView);
                         EditorGUI.BeginDisabled(projectionMatrixMode.hasMultipleDifferentValues || isPhysicalCamera && (focalLength.hasMultipleDifferentValues || sensorSize.hasMultipleDifferentValues));
                         EditorGUI.BeginChangeCheck();
-                        float fovNewValue = EditorGUILayout.Slider(content, fieldOfView.floatValue, 1f, 179f);
+                        float fovNewValue = EditorGUILayout.Slider(content, fieldOfView.floatValue, 0.00001f, 179f);
                         bool fovChanged = EditorGUI.EndChangeCheck();
                         EditorGUI.EndDisabled();
                         EditorGUILayout.EndHorizontal();
diff --git a/Editor/Mono/Inspector/LabelGUI.cs b/Editor/Mono/Inspector/LabelGUI.cs
index c7b69c305f..7ef70781c2 100644
--- a/Editor/Mono/Inspector/LabelGUI.cs
+++ b/Editor/Mono/Inspector/LabelGUI.cs
@@ -189,7 +189,7 @@ public void OnLabelGUI(Object[] assets)
             r.x = widthProbeRect.xMax + labelButton.margin.left;
             if (EditorGUI.DropdownButton(r, GUIContent.none, FocusType.Passive, labelButton))
             {
-                PopupWindow.Show(r, new PopupList(m_AssetLabels), null, ShowMode.PopupMenuWithKeyboardFocus);
+                PopupWindow.Show(r, new PopupList(m_AssetLabels));
             }
 
             EditorGUILayout.EndHorizontal();
@@ -209,7 +209,7 @@ private void DrawLabelList(bool partiallySelected, float xMax)
                 {
                     evt.Use();
                     rt.x = xMax;
-                    PopupWindow.Show(rt, new PopupList(m_AssetLabels, content.text), null, ShowMode.PopupMenuWithKeyboardFocus);
+                    PopupWindow.Show(rt, new PopupList(m_AssetLabels, content.text));
                 }
             }
         }
diff --git a/Editor/Mono/Inspector/LightingSettingsInspector.cs b/Editor/Mono/Inspector/LightingSettingsInspector.cs
index afe116b735..0f5d45dffb 100644
--- a/Editor/Mono/Inspector/LightingSettingsInspector.cs
+++ b/Editor/Mono/Inspector/LightingSettingsInspector.cs
@@ -56,7 +56,6 @@ static class Styles
             public static readonly GUIContent CastShadows = EditorGUIUtility.TrTextContent("Cast Shadows", "Specifies whether a geometry creates shadows or not when a shadow-casting Light shines on it.");
             public static readonly GUIContent ReceiveShadows = EditorGUIUtility.TrTextContent("Receive Shadows", "When enabled, any shadows cast from other objects are drawn on the geometry.");
             public static readonly GUIContent MotionVectors = EditorGUIUtility.TrTextContent("Motion Vectors", "Specifies whether the Mesh renders 'Per Object Motion', 'Camera Motion', or 'No Motion' vectors to the Camera Motion Vector Texture.");
-
             public static readonly GUIContent LightmapInfoBox = EditorGUIUtility.TrTextContent("To enable generation of lightmaps for this Mesh Renderer, please enable the 'Lightmap Static' property.");
             public static readonly GUIContent TerrainLightmapInfoBox = EditorGUIUtility.TrTextContent("To enable generation of lightmaps for this Mesh Renderer, please enable the 'Lightmap Static' property.");
             public static readonly GUIContent ResolutionTooHighWarning = EditorGUIUtility.TrTextContent("Precompute/indirect resolution for this terrain is probably too high. Use a lower realtime/indirect resolution setting in the Lighting window or assign LightmapParameters that use a lower resolution setting. Otherwise it may take a very long time to bake and memory consumption during and after the bake may be very high.");
@@ -157,13 +156,20 @@ public void RenderMeshSettings(bool showLightmapSettings)
             m_GameObjectsSerializedObject.Update();
             m_LightmapSettings.Update();
 
-            EditorGUILayout.PropertyField(m_CastShadows, Styles.CastShadows, true);
+            // TODO(RadeonRays): remove if GPU lightmapper once the feature has been implemented.
+            if (LightmapEditorSettings.lightmapper != LightmapEditorSettings.Lightmapper.ProgressiveGPU)
+                EditorGUILayout.PropertyField(m_CastShadows, Styles.CastShadows, true);
+
             bool isDeferredRenderingPath = SceneView.IsUsingDeferredRenderingPath();
 
             if (SupportedRenderingFeatures.active.rendererSupportsReceiveShadows)
             {
                 using (new EditorGUI.DisabledScope(isDeferredRenderingPath))
-                    EditorGUILayout.PropertyField(m_ReceiveShadows, Styles.ReceiveShadows, true);
+                {
+                    // TODO(RadeonRays): remove if GPU lightmapper once the feature has been implemented.
+                    if (LightmapEditorSettings.lightmapper != LightmapEditorSettings.Lightmapper.ProgressiveGPU)
+                        EditorGUILayout.PropertyField(m_ReceiveShadows, Styles.ReceiveShadows, true);
+                }
             }
 
             if (SupportedRenderingFeatures.active.rendererSupportsMotionVectors)
diff --git a/Editor/Mono/Inspector/MaterialEditorGUIHelpers.cs b/Editor/Mono/Inspector/MaterialEditorGUIHelpers.cs
index 77dcd09308..f585af937f 100644
--- a/Editor/Mono/Inspector/MaterialEditorGUIHelpers.cs
+++ b/Editor/Mono/Inspector/MaterialEditorGUIHelpers.cs
@@ -163,6 +163,7 @@ public bool DoubleSidedGIField()
             }
             else
             {
+                // TODO(RadeonRays): change this to (lightmapper == Enlighten) once Double Sided GI works with GPU lightmapper.
                 using (new EditorGUI.DisabledScope(LightmapEditorSettings.lightmapper != LightmapEditorSettings.Lightmapper.ProgressiveCPU))
                     EditorGUI.Toggle(r, Styles.doubleSidedGILabel, false);
             }
diff --git a/Editor/Mono/Inspector/PlayerSettingsEditor/PlayerSettingsEditor.cs b/Editor/Mono/Inspector/PlayerSettingsEditor/PlayerSettingsEditor.cs
index 2c022b45dc..7d97663c9a 100644
--- a/Editor/Mono/Inspector/PlayerSettingsEditor/PlayerSettingsEditor.cs
+++ b/Editor/Mono/Inspector/PlayerSettingsEditor/PlayerSettingsEditor.cs
@@ -168,6 +168,7 @@ class SettingsContent
             public static readonly GUIContent managedStrippingLevel = EditorGUIUtility.TrTextContent("Managed Stripping Level", "If scripting backend is IL2CPP, managed stripping can't be disabled.");
             public static readonly GUIContent il2cppCompilerConfiguration = EditorGUIUtility.TrTextContent("C++ Compiler Configuration");
             public static readonly GUIContent scriptingMono2x = EditorGUIUtility.TrTextContent("Mono");
+            public static readonly GUIContent scriptingMono2xDeprecated = EditorGUIUtility.TrTextContent("Mono (Deprecated)");
             public static readonly GUIContent scriptingWinRTDotNET = EditorGUIUtility.TrTextContent(".NET");
             public static readonly GUIContent scriptingIL2CPP = EditorGUIUtility.TrTextContent("IL2CPP");
             public static readonly GUIContent scriptingDefault = EditorGUIUtility.TrTextContent("Default");
@@ -1697,10 +1698,10 @@ private void OtherSectionRenderingGUI(BuildPlatform platform, BuildTargetGroup t
                     EditorGUI.BeginChangeCheck();
                     LightmapEncodingQuality encodingQuality = PlayerSettings.GetLightmapEncodingQualityForPlatformGroup(targetGroup);
                     LightmapEncodingQuality[] lightmapEncodingValues = {LightmapEncodingQuality.Normal, LightmapEncodingQuality.High};
-                    encodingQuality = BuildEnumPopup(SettingsContent.lightmapEncodingLabel, encodingQuality, lightmapEncodingValues, SettingsContent.lightmapEncodingNames);
-                    if (EditorGUI.EndChangeCheck())
+                    LightmapEncodingQuality newEncodingQuality = BuildEnumPopup(SettingsContent.lightmapEncodingLabel, encodingQuality, lightmapEncodingValues, SettingsContent.lightmapEncodingNames);
+                    if (EditorGUI.EndChangeCheck() && encodingQuality != newEncodingQuality)
                     {
-                        PlayerSettings.SetLightmapEncodingQualityForPlatformGroup(targetGroup, encodingQuality);
+                        PlayerSettings.SetLightmapEncodingQualityForPlatformGroup(targetGroup, newEncodingQuality);
 
                         Lightmapping.OnUpdateLightmapEncoding(targetGroup);
 
@@ -1961,6 +1962,7 @@ private void OtherSectionConfigurationGUI(BuildTargetGroup targetGroup, ISetting
                 ScriptingImplementation currBackend = PlayerSettings.GetScriptingBackend(targetGroup);
                 currentBackendIsIl2Cpp = currBackend == ScriptingImplementation.IL2CPP;
                 ScriptingImplementation newBackend;
+                var mono2xDeprecated = targetGroup == BuildTargetGroup.iOS;
 
                 if (targetGroup == BuildTargetGroup.tvOS)
                 {
@@ -1970,11 +1972,11 @@ private void OtherSectionConfigurationGUI(BuildTargetGroup targetGroup, ISetting
                 else if (backends.Length == 1)
                 {
                     newBackend = backends[0];
-                    BuildDisabledEnumPopup(GetNiceScriptingBackendName(backends[0]), SettingsContent.scriptingBackend);
+                    BuildDisabledEnumPopup(GetNiceScriptingBackendName(backends[0], mono2xDeprecated), SettingsContent.scriptingBackend);
                 }
                 else
                 {
-                    newBackend = BuildEnumPopup(SettingsContent.scriptingBackend, currBackend, backends, GetNiceScriptingBackendNames(backends));
+                    newBackend = BuildEnumPopup(SettingsContent.scriptingBackend, currBackend, backends, GetNiceScriptingBackendNames(backends, mono2xDeprecated));
                 }
 
                 if (targetGroup == BuildTargetGroup.iOS && newBackend == ScriptingImplementation.Mono2x)
@@ -2313,7 +2315,6 @@ private void OtherSectionLegacyGUI()
             EditorGUILayout.Space();
         }
 
-        private static Dictionary<ScriptingImplementation, GUIContent> m_NiceScriptingBackendNames;
         private static Dictionary<ApiCompatibilityLevel, GUIContent> m_NiceApiCompatibilityLevelNames;
         private static Dictionary<ManagedStrippingLevel, GUIContent> m_NiceManagedStrippingLevelNames;
 
@@ -2331,31 +2332,26 @@ private static GUIContent[] GetGUIContentsForValues<T>(Dictionary<T, GUIContent>
             return names;
         }
 
-        private static GUIContent[] GetNiceScriptingBackendNames(ScriptingImplementation[] scriptingBackends)
+        static GUIContent[] GetNiceScriptingBackendNames(ScriptingImplementation[] scriptingBackends, bool mono2xDeprecated)
         {
-            InitializeNiceScriptingBackendNames();
-            return GetGUIContentsForValues(m_NiceScriptingBackendNames, scriptingBackends);
+            return scriptingBackends.Select(s => GetNiceScriptingBackendName(s, mono2xDeprecated)).ToArray();
         }
 
-        static void InitializeNiceScriptingBackendNames()
+        static GUIContent GetNiceScriptingBackendName(ScriptingImplementation scriptingBackend, bool mono2xDeprecated)
         {
-            if (m_NiceScriptingBackendNames == null)
+            switch (scriptingBackend)
             {
-                m_NiceScriptingBackendNames = new Dictionary<ScriptingImplementation, GUIContent>
-                {
-                    { ScriptingImplementation.Mono2x, SettingsContent.scriptingMono2x },
-                    { ScriptingImplementation.WinRTDotNET, SettingsContent.scriptingWinRTDotNET },
-                    { ScriptingImplementation.IL2CPP, SettingsContent.scriptingIL2CPP }
-                };
+                case ScriptingImplementation.Mono2x:
+                    return mono2xDeprecated ? SettingsContent.scriptingMono2xDeprecated : SettingsContent.scriptingMono2x;
+                case ScriptingImplementation.IL2CPP:
+                    return SettingsContent.scriptingIL2CPP;
+                case ScriptingImplementation.WinRTDotNET:
+                    return SettingsContent.scriptingWinRTDotNET;
+                default:
+                    throw new ArgumentException($"Scripting backend value {scriptingBackend} is not supported.", nameof(scriptingBackend));
             }
         }
 
-        private static GUIContent GetNiceScriptingBackendName(ScriptingImplementation scriptingBackend)
-        {
-            InitializeNiceScriptingBackendNames();
-            return GetGUIContentsForValues(m_NiceScriptingBackendNames, new[] { scriptingBackend }).First();
-        }
-
         private static GUIContent[] GetNiceApiCompatibilityLevelNames(ApiCompatibilityLevel[] apiCompatibilityLevels)
         {
             if (m_NiceApiCompatibilityLevelNames == null)
diff --git a/Editor/Mono/Inspector/RectTransformEditor.cs b/Editor/Mono/Inspector/RectTransformEditor.cs
index 3ee6543a67..a98c23be5b 100644
--- a/Editor/Mono/Inspector/RectTransformEditor.cs
+++ b/Editor/Mono/Inspector/RectTransformEditor.cs
@@ -298,7 +298,7 @@ void LayoutDropdownButton(bool anyWithoutParent)
                 {
                     GUIUtility.keyboardControl = 0;
                     m_DropdownWindow = new LayoutDropdownWindow(serializedObject);
-                    PopupWindow.Show(dropdownPosition, m_DropdownWindow, null, ShowMode.PopupMenuWithKeyboardFocus);
+                    PopupWindow.Show(dropdownPosition, m_DropdownWindow);
                 }
                 GUI.color = oldColor;
             }
diff --git a/Editor/Mono/Inspector/TagManagerInspector.cs b/Editor/Mono/Inspector/TagManagerInspector.cs
index 4d6d4b4f38..b4548b6da4 100644
--- a/Editor/Mono/Inspector/TagManagerInspector.cs
+++ b/Editor/Mono/Inspector/TagManagerInspector.cs
@@ -175,7 +175,7 @@ void NewElement(Rect buttonRect, ReorderableList list)
         {
             buttonRect.x -= 400;
             buttonRect.y -= 13;
-            PopupWindow.Show(buttonRect, new EnterNamePopup(m_Tags, s => { InternalEditorUtility.AddTag(s); }), null, ShowMode.PopupMenuWithKeyboardFocus);
+            PopupWindow.Show(buttonRect, new EnterNamePopup(m_Tags, s => { InternalEditorUtility.AddTag(s); }));
         }
 
         private void RemoveFromTagsList(ReorderableList list)
diff --git a/Editor/Mono/Inspector/TextureInspector.cs b/Editor/Mono/Inspector/TextureInspector.cs
index 86ba109b6e..ab99053c9b 100644
--- a/Editor/Mono/Inspector/TextureInspector.cs
+++ b/Editor/Mono/Inspector/TextureInspector.cs
@@ -2,8 +2,10 @@
 // Copyright (c) Unity Technologies. For terms of use, see
 // https://unity3d.com/legal/licenses/Unity_Reference_Only_License
 
+using System.Collections.Generic;
 using UnityEngine;
 using UnityEditor;
+using UnityEngine.Rendering;
 
 
 namespace UnityEditor
@@ -48,8 +50,9 @@ internal class TextureInspector : Editor
     {
         class Styles
         {
-            public GUIContent smallZoom, largeZoom, alphaIcon, RGBIcon;
+            public GUIContent smallZoom, largeZoom;
             public GUIStyle previewButton, previewSlider, previewSliderThumb, previewLabel;
+            public GUIStyle previewButtonRed, previewButtonGreen, previewButtonBlue;
 
             public readonly GUIContent wrapModeLabel = EditorGUIUtility.TrTextContent("Wrap Mode");
             public readonly GUIContent wrapU = EditorGUIUtility.TrTextContent("U axis");
@@ -77,9 +80,11 @@ public Styles()
             {
                 smallZoom = EditorGUIUtility.IconContent("PreTextureMipMapLow");
                 largeZoom = EditorGUIUtility.IconContent("PreTextureMipMapHigh");
-                alphaIcon = EditorGUIUtility.IconContent("PreTextureAlpha");
-                RGBIcon = EditorGUIUtility.IconContent("PreTextureRGB");
+
                 previewButton = "preButton";
+                previewButtonRed = "preButtonRed";
+                previewButtonGreen = "preButtonGreen";
+                previewButtonBlue = "preButtonBlue";
                 previewSlider = "preSlider";
                 previewSliderThumb = "preSliderThumb";
                 previewLabel = "preLabelUpper";
@@ -87,8 +92,20 @@ public Styles()
         }
         static Styles s_Styles;
 
-        private bool m_ShowAlpha;
-        public bool showAlpha {  get { return m_ShowAlpha; } }
+        enum PreviewMode
+        {
+            RGB,
+            R,
+            G,
+            B,
+            A,
+        };
+
+        private PreviewMode m_PreviewMode = PreviewMode.RGB;
+        public bool showAlpha
+        {
+            get { return m_PreviewMode == PreviewMode.A; }
+        }
 
         // Plain Texture
         protected SerializedProperty m_WrapU;
@@ -410,7 +427,6 @@ public override void OnPreviewSettings()
             // and while it's being shown the actual texture object might disappear --
             // make sure to handle null targets.
             Texture tex = target as Texture;
-            bool showMode = true;
             bool alphaOnly = false;
             bool hasAlpha = true;
             int mipCount = 1;
@@ -448,19 +464,53 @@ public override void OnPreviewSettings()
                 mipCount = Mathf.Max(mipCount, TextureUtil.GetMipmapCount(t));
             }
 
+
+            List<PreviewMode> previewCandidates = new List<PreviewMode>(5);
+            previewCandidates.Add(PreviewMode.RGB);
+            previewCandidates.Add(PreviewMode.R);
+            previewCandidates.Add(PreviewMode.G);
+            previewCandidates.Add(PreviewMode.B);
+            previewCandidates.Add(PreviewMode.A);
+
             if (alphaOnly)
             {
-                m_ShowAlpha = true;
-                showMode = false;
+                previewCandidates.Clear();
+                previewCandidates.Add(PreviewMode.A);
+                m_PreviewMode = PreviewMode.A;
             }
             else if (!hasAlpha)
             {
-                m_ShowAlpha = false;
-                showMode = false;
+                previewCandidates.Remove(PreviewMode.A);
             }
 
-            if (showMode && tex != null && !IsNormalMap(tex))
-                m_ShowAlpha = GUILayout.Toggle(m_ShowAlpha, m_ShowAlpha ? s_Styles.alphaIcon : s_Styles.RGBIcon, s_Styles.previewButton);
+
+            if (previewCandidates.Count > 1 && tex != null && !IsNormalMap(tex))
+            {
+                int selectedIndex = previewCandidates.IndexOf(m_PreviewMode);
+                if (selectedIndex == -1)
+                    selectedIndex = 0;
+
+                if (previewCandidates.Contains(PreviewMode.RGB))
+                    m_PreviewMode = GUILayout.Toggle(m_PreviewMode == PreviewMode.RGB, "RGB", s_Styles.previewButton)
+                        ? PreviewMode.RGB
+                        : m_PreviewMode;
+                if (previewCandidates.Contains(PreviewMode.R))
+                    m_PreviewMode = GUILayout.Toggle(m_PreviewMode == PreviewMode.R, "R", s_Styles.previewButtonRed)
+                        ? PreviewMode.R
+                        : m_PreviewMode;
+                if (previewCandidates.Contains(PreviewMode.G))
+                    m_PreviewMode = GUILayout.Toggle(m_PreviewMode == PreviewMode.G, "G", s_Styles.previewButtonGreen)
+                        ? PreviewMode.G
+                        : m_PreviewMode;
+                if (previewCandidates.Contains(PreviewMode.B))
+                    m_PreviewMode = GUILayout.Toggle(m_PreviewMode == PreviewMode.B, "B", s_Styles.previewButtonBlue)
+                        ? PreviewMode.B
+                        : m_PreviewMode;
+                if (previewCandidates.Contains(PreviewMode.A))
+                    m_PreviewMode = GUILayout.Toggle(m_PreviewMode == PreviewMode.A, "A", s_Styles.previewButton)
+                        ? PreviewMode.A
+                        : m_PreviewMode;
+            }
 
             if (mipCount > 1)
             {
@@ -512,14 +562,33 @@ public override void OnPreviewGUI(Rect r, GUIStyle background)
             PreviewGUI.BeginScrollView(r, m_Pos, wantedRect, "PreHorizontalScrollbar", "PreHorizontalScrollbarThumb");
             FilterMode oldFilter = t.filterMode;
             TextureUtil.SetFilterModeNoDirty(t, FilterMode.Point);
-
             Texture2D t2d = t as Texture2D;
-            if (m_ShowAlpha)
+            ColorWriteMask colorWriteMask = ColorWriteMask.All;
+
+            switch (m_PreviewMode)
+            {
+                case PreviewMode.R:
+                    colorWriteMask = ColorWriteMask.Red | ColorWriteMask.Alpha;
+                    break;
+                case PreviewMode.G:
+                    colorWriteMask = ColorWriteMask.Green | ColorWriteMask.Alpha;
+                    break;
+                case PreviewMode.B:
+                    colorWriteMask = ColorWriteMask.Blue | ColorWriteMask.Alpha;
+                    break;
+            }
+
+            if (m_PreviewMode == PreviewMode.A)
+            {
                 EditorGUI.DrawTextureAlpha(wantedRect, t, ScaleMode.StretchToFill, 0, mipLevel);
-            else if (t2d != null && t2d.alphaIsTransparency)
-                EditorGUI.DrawTextureTransparent(wantedRect, t, ScaleMode.StretchToFill, 0, mipLevel);
+            }
             else
-                EditorGUI.DrawPreviewTexture(wantedRect, t, null, ScaleMode.StretchToFill, 0, mipLevel);
+            {
+                if (t2d != null && t2d.alphaIsTransparency)
+                    EditorGUI.DrawTextureTransparent(wantedRect, t, ScaleMode.StretchToFill, 0, mipLevel, colorWriteMask);
+                else
+                    EditorGUI.DrawPreviewTexture(wantedRect, t, null, ScaleMode.StretchToFill, 0, mipLevel, colorWriteMask);
+            }
 
             // TODO: Less hacky way to prevent sprite rects to not appear in smaller previews like icons.
             if (wantedRect.width > 32 && wantedRect.height > 32)
diff --git a/Editor/Mono/LookDevView/LookDevView.cs b/Editor/Mono/LookDevView/LookDevView.cs
index ceadf35366..4709caf02b 100644
--- a/Editor/Mono/LookDevView/LookDevView.cs
+++ b/Editor/Mono/LookDevView/LookDevView.cs
@@ -1676,7 +1676,7 @@ private void HandleDragging()
                         }
 
                         GameObject go = o as GameObject;
-                        if (go && EditorUtility.IsPersistent(go) && PrefabUtility.GetPrefabObject(go) != null)
+                        if (go && EditorUtility.IsPersistent(go) && PrefabUtility.IsPartOfPrefabAsset(go))
                         {
                             if (GameObjectInspector.HasRenderableParts(go))
                             {
diff --git a/Editor/Mono/Prefabs/PrefabUtility.bindings.cs b/Editor/Mono/Prefabs/PrefabUtility.bindings.cs
index 7953e088d2..499f70164c 100644
--- a/Editor/Mono/Prefabs/PrefabUtility.bindings.cs
+++ b/Editor/Mono/Prefabs/PrefabUtility.bindings.cs
@@ -30,6 +30,7 @@ public sealed partial class PrefabUtility
         extern private static Object GetCorrespondingObjectFromSourceAtPath_internal([NotNull] Object obj, string prefabAssetPath);
 
         // Retrieves the prefab object representation.
+        [Obsolete("Use GetPrefabInstanceHandle for Prefab instances. Handles for Prefab Assets has been discontinued.")]
         [StaticAccessor("PrefabUtilityBindings", StaticAccessorType.DoubleColon)]
         extern public static Object GetPrefabObject(Object targetObject);
 
@@ -72,6 +73,7 @@ public sealed partial class PrefabUtility
         extern public static void MergeAllPrefabInstances(Object targetObject);
 
         // Disconnects the prefab instance from its parent prefab.
+        [Obsolete("The concept of disconnecting Prefab instances has been deprecated.")]
         [FreeFunction]
         extern public static void DisconnectPrefabInstance(Object targetObject);
 
@@ -88,6 +90,7 @@ public sealed partial class PrefabUtility
         extern public static void LoadPrefabContentsIntoPreviewScene(string prefabPath, Scene scene);
 
         // Connect the source prefab to the game object, which replaces the instance content with the content of the prefab
+        [Obsolete("Use RevertPrefabInstance. Prefabs instances can no longer be connected to Prefab Assets they are not an instance of to begin with.")]
         [StaticAccessor("PrefabUtilityBindings", StaticAccessorType.DoubleColon)]
         [NativeThrows]
         extern public static GameObject ConnectGameObjectToPrefab([NotNull] GameObject go, [NotNull] GameObject sourcePrefab);
@@ -105,26 +108,35 @@ public sealed partial class PrefabUtility
 
         // Connects the game object to the prefab that it was last connected to.
         [FreeFunction]
+        [Obsolete("Use RevertPrefabInstance.")]
         extern public static bool ReconnectToLastPrefab(GameObject go);
 
         // Resets the properties of the component or game object to the parent prefab state
+        [Obsolete("Use RevertObjectOverride.")]
         [StaticAccessor("PrefabUtilityBindings", StaticAccessorType.DoubleColon)]
         extern public static bool ResetToPrefabState(Object obj);
 
+        // Resets the properties of the component or game object to the parent prefab state
+        [NativeMethod("PrefabUtilityBindings::ResetToPrefabState", IsFreeFunction = true)]
+        extern private static bool RevertObjectOverride_Internal(Object obj);
+
         [FreeFunction]
         extern public static bool IsAddedComponentOverride([NotNull] Object component);
 
         // Resets the properties of all objects in the prefab, including child game objects and components that were added to the prefab instance
+        [Obsolete("Use the overload that takes an InteractionMode parameter.")]
         [FreeFunction]
         extern public static bool RevertPrefabInstance([NotNull] GameObject go);
 
+        // Resets the properties of all objects in the prefab, including child game objects and components that were added to the prefab instance
+        [NativeMethod("RevertPrefabInstance", IsFreeFunction = true)]
+        extern private static bool RevertPrefabInstance_Internal([NotNull] GameObject go);
+
         // Helper function to find the prefab root of an object
         [FreeFunction]
         [Obsolete("Use GetOutermostPrefabInstanceRoot if source is a Prefab instance or source.transform.root.gameObject if source is a Prefab Asset object.")]
         extern public static GameObject FindPrefabRoot([NotNull] GameObject source);
 
-#pragma warning disable 0618 // Type or member is obsolete
-
         internal static GameObject CreateVariant(GameObject assetRoot, string path)
         {
             if (assetRoot == null)
@@ -146,11 +158,16 @@ internal static GameObject CreateVariant(GameObject assetRoot, string path)
             if (!Paths.IsValidAssetPath(path, ".prefab"))
                 throw new ArgumentException("Given path is not valid: '" + path + "'");
 
+#pragma warning disable 0618 // Type or member is obsolete
             return CreateVariant_Internal(assetRoot, path, ReplacePrefabOptions.Default);
+#pragma warning restore 0618 // Type or member is obsolete
         }
 
+        // TODO: Having an non-obsolete method that takes an obsolete enum types as parameter is no good.
         [NativeMethod("CreateVariant", IsFreeFunction = true)]
+#pragma warning disable 0618 // Type or member is obsolete
         extern private static GameObject CreateVariant_Internal([NotNull] GameObject original, string path, ReplacePrefabOptions replaceOptions);
+#pragma warning restore 0618 // Type or member is obsolete
 
         private enum PrefabCreationFlags
         {
@@ -158,6 +175,8 @@ private enum PrefabCreationFlags
             CreateVariant = 1,
         }
 
+        // TODO: Having an non-obsolete method that takes an obsolete enum types as parameter is no good.
+#pragma warning disable 0618 // Type or member is obsolete
         private static GameObject SavePrefab(GameObject inputObject, string path, ReplacePrefabOptions replaceOptions, PrefabCreationFlags creationFlags)
         {
             if (inputObject == null)
@@ -175,13 +194,17 @@ private static GameObject SavePrefab(GameObject inputObject, string path, Replac
                 throw new ArgumentException("Given path does not exist: '" + path + "'");
 
             string prefabGUID = AssetDatabase.AssetPathToGUID(path);
-            if (!VerifyNestingFromScript(new GameObject[] {inputObject}, prefabGUID, PrefabUtility.GetPrefabObject(inputObject)))
+            if (!VerifyNestingFromScript(new GameObject[] {inputObject}, prefabGUID, PrefabUtility.GetPrefabInstanceHandle(inputObject)))
                 throw new ArgumentException("Cyclic nesting detected");
 
             return SavePrefab_Internal(inputObject, path, replaceOptions, creationFlags);
         }
 
+#pragma warning restore 0618 // Type or member is obsolete
+
+        // TODO: Having an non-obsolete method that takes an obsolete enum types as parameter is no good.
         [NativeMethod("SavePrefab", IsFreeFunction = true)]
+#pragma warning disable 0618 // Type or member is obsolete
         extern private static GameObject SavePrefab_Internal([NotNull] GameObject root, string path, ReplacePrefabOptions replaceOptions, PrefabCreationFlags createOptions);
 #pragma warning restore 0618 // Type or member is obsolete
 
@@ -201,7 +224,7 @@ internal static void AddGameObjectsToPrefabAndConnect(GameObject[] gameObjects,
 
             Object targetPrefabInstance = null;
 
-            var targetPrefabObject = PrefabUtility.GetPrefabObject(targetPrefab);
+            var targetPrefabObject = PrefabUtility.GetPrefabAssetHandle(targetPrefab);
 
             foreach (GameObject go in gameObjects)
             {
@@ -232,7 +255,7 @@ internal static void AddGameObjectsToPrefabAndConnect(GameObject[] gameObjects,
                 if (PrefabUtility.IsPartOfNonAssetPrefabInstance(go))
                 {
                     var correspondingGO = PrefabUtility.GetCorrespondingObjectFromSource(go);
-                    var correspondingGOPrefabObject = PrefabUtility.GetPrefabObject(correspondingGO);
+                    var correspondingGOPrefabObject = PrefabUtility.GetPrefabAssetHandle(correspondingGO);
                     if (targetPrefabObject == correspondingGOPrefabObject)
                         throw new ArgumentException("GameObject is already part of target prefab");
                 }
@@ -299,6 +322,11 @@ internal static void AddGameObjectsToPrefabAndConnect(GameObject[] gameObjects,
         [FreeFunction]
         extern public static bool IsPartOfVariantPrefab([NotNull] Object componentOrGameObject);
 
+        // Returns true if the object is from a Prefab Asset which is not editable, or an instance of such a Prefab
+        // Examples are Model Prefabs and Prefabs in read-only folders.
+        [FreeFunction]
+        extern public static bool IsPartOfImmutablePrefab([NotNull] Object componentOrGameObject);
+
         [FreeFunction]
         extern public static bool IsDisconnectedFromPrefabAsset([NotNull] Object componentOrGameObject);
 
diff --git a/Editor/Mono/Prefabs/PrefabUtility.cs b/Editor/Mono/Prefabs/PrefabUtility.cs
index 8279a9f737..869694c941 100644
--- a/Editor/Mono/Prefabs/PrefabUtility.cs
+++ b/Editor/Mono/Prefabs/PrefabUtility.cs
@@ -296,10 +296,7 @@ public static void RevertPrefabInstance(GameObject instanceRoot, InteractionMode
 
             CheckInstanceIsNotPersistent(instanceRoot);
 
-            // The concept of disconnecting are being deprecated. For now use FindRootGameObjectWithSameParentPrefab
-            // to re-connect existing disconnected prefabs.
-            #pragma warning disable 0618 // Type or member is obsolete
-            GameObject prefabInstanceRoot = FindRootGameObjectWithSameParentPrefab(instanceRoot);
+            GameObject prefabInstanceRoot = GetOutermostPrefabInstanceRoot(instanceRoot);
 
             var actionName = "Revert Prefab Instance";
             HashSet<int> hierarchy = null;
@@ -313,13 +310,13 @@ public static void RevertPrefabInstance(GameObject instanceRoot, InteractionMode
 
             if (isDisconnected)
             {
-                ReconnectToLastPrefab(prefabInstanceRoot);
+                RevertPrefabInstance_Internal(prefabInstanceRoot);
 
                 if (action == InteractionMode.UserAction)
                     Undo.RegisterCreatedObjectUndo(GetPrefabInstanceHandle(prefabInstanceRoot), actionName);
             }
 
-            RevertPrefabInstance(prefabInstanceRoot);
+            RevertPrefabInstance_Internal(prefabInstanceRoot);
 
             if (action == InteractionMode.UserAction)
             {
@@ -333,10 +330,7 @@ public static void ApplyPrefabInstance(GameObject instanceRoot, InteractionMode
 
             CheckInstanceIsNotPersistent(instanceRoot);
 
-            // The concept of disconnecting are being deprecated. For now use FindRootGameObjectWithSameParentPrefab
-            // to re-connect existing disconnected prefabs.
-            #pragma warning disable 0618 // Type or member is obsolete
-            GameObject prefabInstanceRoot = FindRootGameObjectWithSameParentPrefab(instanceRoot);
+            GameObject prefabInstanceRoot = GetOutermostPrefabInstanceRoot(instanceRoot);
 
             var actionName = "Apply instance to prefab";
             Object correspondingSourceObject = GetCorrespondingObjectFromSource(prefabInstanceRoot);
@@ -525,7 +519,7 @@ public static void RevertObjectOverride(Object instanceComponentOrGameObject, In
 
             if (action == InteractionMode.UserAction)
                 Undo.RegisterCompleteObjectUndo(instanceComponentOrGameObject, "Revert component property overrides");
-            PrefabUtility.ResetToPrefabState(instanceComponentOrGameObject);
+            PrefabUtility.RevertObjectOverride_Internal(instanceComponentOrGameObject);
         }
 
         public static void ApplyAddedComponent(Component component, string assetPath, InteractionMode action)
@@ -598,7 +592,7 @@ private static bool IsPrefabInstanceObjectOf(Object instance, Object source)
                     return true;
                 }
 
-                if (GetPrefabObject(o) == source)
+                if (GetPrefabAssetHandle(o) == source)
                 {
                     return true;
                 }
@@ -641,7 +635,7 @@ public static void ApplyRemovedComponent(GameObject instanceGameObject, Componen
                 SavePrefabAsset(prefabAsset);
             }
 
-            var prefabInstanceObject = PrefabUtility.GetPrefabObject(instanceGameObject);
+            var prefabInstanceObject = PrefabUtility.GetPrefabInstanceHandle(instanceGameObject);
 
             if (action == InteractionMode.UserAction)
                 Undo.RegisterCompleteObjectUndo(prefabInstanceObject, actionName);
@@ -682,7 +676,7 @@ public static void RevertRemovedComponent(GameObject instanceGameObject, Compone
             CheckInstanceIsNotPersistent(instanceGameObject);
 
             var actionName = "Revert Prefab removed component";
-            var prefabInstanceObject = PrefabUtility.GetPrefabObject(instanceGameObject);
+            var prefabInstanceObject = PrefabUtility.GetPrefabInstanceHandle(instanceGameObject);
 
             if (action == InteractionMode.UserAction)
                 Undo.RegisterCompleteObjectUndo(instanceGameObject, actionName);
@@ -928,7 +922,7 @@ public static Object GetPrefabParent(Object obj)
         }
 
         // Creates an empty prefab at given path.
-        // TODO Steen Lund 2017 11 28 This needs to be marked OBSOLETE
+        [Obsolete("The concept of creating a completely empty Prefab has been discontinued. You can however use SaveAsPrefabAsset with an empty GameObject.")]
         public static Object CreateEmptyPrefab(string path)
         {
             // This is here to simulate previous behaviour
@@ -944,8 +938,6 @@ public static Object CreateEmptyPrefab(string path)
             return PrefabUtility.GetPrefabObject(assetObject);
         }
 
-#pragma warning disable CS0618 // Type or member is obsolete
-
         public static GameObject SavePrefabAsset(GameObject asset)
         {
             if (asset == null)
@@ -966,7 +958,9 @@ public static GameObject SavePrefabAsset(GameObject asset)
             if (root != asset)
                 throw new ArgumentException("GameObject to save Prefab from must be a Prefab root");
 
+#pragma warning disable CS0618 // Type or member is obsolete
             return SavePrefab(root, path, ReplacePrefabOptions.Default, PrefabCreationFlags.None);
+#pragma warning restore CS0618 // Type or member is obsolete
         }
 
         private static void SaveAsPrefabAssetArgumentCheck(GameObject root)
@@ -1002,7 +996,9 @@ public static GameObject SaveAsPrefabAsset(GameObject root, string assetPath)
             if (IsPrefabInstanceRoot(root))
                 creationFlags = PrefabCreationFlags.CreateVariant;
 
+#pragma warning disable CS0618 // Type or member is obsolete
             return SavePrefab(root, assetPath, ReplacePrefabOptions.Default, creationFlags);
+#pragma warning restore CS0618 // Type or member is obsolete
         }
 
         public static GameObject SaveAsPrefabAssetAndConnect(GameObject root, string assetPath, InteractionMode action)
@@ -1020,7 +1016,9 @@ public static GameObject SaveAsPrefabAssetAndConnect(GameObject root, string ass
             if (IsPrefabInstanceRoot(root))
                 creationFlags = PrefabCreationFlags.CreateVariant;
 
+#pragma warning disable CS0618 // Type or member is obsolete
             var assetRoot = SavePrefab(root, assetPath, ReplacePrefabOptions.ConnectToPrefab, creationFlags);
+#pragma warning restore CS0618 // Type or member is obsolete
 
             if (action == InteractionMode.UserAction)
             {
@@ -1049,7 +1047,7 @@ internal static void ApplyPrefabInstance(GameObject instance)
             {
                 // The concept of disconnecting are being deprecated. For now use FindRootGameObjectWithSameParentPrefab
                 // to re-connect existing disconnected prefabs.
-                var validRoot = PrefabUtility.FindValidUploadPrefabInstanceRoot(instance);
+                var validRoot = PrefabUtility.GetOutermostPrefabInstanceRoot(instance);
                 var ok = validRoot == instance;
                 if (!ok && PrefabUtility.GetCorrespondingObjectFromOriginalSource(instance) != PrefabUtility.GetCorrespondingObjectFromSource(instance))
                     throw new ArgumentException("Can't save Prefab from an object that originates from a nested Prefab");
@@ -1063,11 +1061,17 @@ internal static void ApplyPrefabInstance(GameObject instance)
 
             var assetObject = GetCorrespondingObjectFromSource(instance);
             string path = AssetDatabase.GetAssetPath(assetObject);
+
+#pragma warning disable CS0618 // Type or member is obsolete
             SavePrefab(instance, path, ReplacePrefabOptions.ConnectToPrefab, PrefabCreationFlags.None);
+#pragma warning restore CS0618 // Type or member is obsolete
         }
 
+        // TOOO: Remove entirely once regular methods handle merging
+        // based on both ids and names on a smarter and more granular level.
         internal static GameObject ReplacePrefabAssetNameBased(GameObject root, string targetPrefab, bool connectToInstance)
         {
+#pragma warning disable CS0618 // Type or member is obsolete
             var options = ReplacePrefabOptions.ReplaceNameBased;
             if (connectToInstance)
                 options |= ReplacePrefabOptions.ConnectToPrefab;
@@ -1076,8 +1080,7 @@ internal static GameObject ReplacePrefabAssetNameBased(GameObject root, string t
 
             if (IsPartOfNonAssetPrefabInstance(root))
             {
-                var instanceRoot = PrefabUtility.GetPrefabInstanceRootGameObject(root);
-                if (root != instanceRoot)
+                if (!IsOutermostPrefabInstanceRoot(root))
                     throw new ArgumentException("Can't replace with part of Prefab instance. Please specify instance root object or a non-instance object.");
 
                 createOptions = PrefabCreationFlags.CreateVariant;
@@ -1087,18 +1090,17 @@ internal static GameObject ReplacePrefabAssetNameBased(GameObject root, string t
                 throw new ArgumentException("Argument connectToInstance is true but root object is an asset not an instance");
 
             return SavePrefab(root, targetPrefab, options, createOptions);
-        }
-
 #pragma warning restore CS0618 // Type or member is obsolete
+        }
 
-        //[Obsolete("CreatePrefab() has been deprecated. Use SavePrefab() instead (UnityUpgradable) -> SavePrefab(go, path, ReplacePrefabOptions.Default)")]
+        // Can't use UnityUpgradable since it doesn't currently support swapping parameter order.
+        [Obsolete("Use SaveAsPrefabAsset instead.")]
         public static GameObject CreatePrefab(string path, GameObject go)
         {
             return SaveAsPrefabAsset(go, path);
         }
 
-        //[Obsolete("CreatePrefab() has been deprecated. Use SavePrefab() instead (UnityUpgradable) -> SavePrefab(go, path, options)")]
-#pragma warning disable CS0618 // Type or member is obsolete
+        [Obsolete("Use SaveAsPrefabAsset or SaveAsPrefabAssetAndConnect instead.")]
         public static GameObject CreatePrefab(string path, GameObject go, ReplacePrefabOptions options)
         {
             if (options == ReplacePrefabOptions.ConnectToPrefab)
@@ -1119,11 +1121,13 @@ public static Object InstantiatePrefab(Object assetComponentOrGameObject, Scene
             return InstantiatePrefab_internal(assetComponentOrGameObject, destinationScene);
         }
 
+        [Obsolete("Use SaveAsPrefabAsset with a path instead.")]
         public static GameObject ReplacePrefab(GameObject go, Object targetPrefab)
         {
             return ReplacePrefab(go, targetPrefab, ReplacePrefabOptions.Default);
         }
 
+        [Obsolete("Use SaveAsPrefabAsset or SaveAsPrefabAssetAndConnect with a path instead.")]
         public static GameObject ReplacePrefab(GameObject go, Object targetPrefab, ReplacePrefabOptions replaceOptions)
         {
             var targetPrefabObject = PrefabUtility.GetPrefabObject(targetPrefab);
@@ -1163,8 +1167,6 @@ public static GameObject ReplacePrefab(GameObject go, Object targetPrefab, Repla
             return SavePrefab(go, assetPath, replaceOptions, PrefabCreationFlags.None);
         }
 
-#pragma warning restore CS0618 // Type or member is obsolete
-
         // Returns the corresponding object from its immediate source, or null if it can't be found.
         public static TObject GetCorrespondingObjectFromSource<TObject>(TObject componentOrGameObject) where TObject : Object
         {
@@ -1211,7 +1213,6 @@ private static Object GetCorrespondingObjectFromOriginalSource_Internal(Object i
         }
 
         // Given an object, returns its prefab type (None, if it's not a prefab)
-#pragma warning disable CS0618 // Type or member is obsolete
         [Obsolete("Use GetPrefabAssetType and GetPrefabInstanceStatus to get the full picture about Prefab types.")]
         public static PrefabType GetPrefabType(Object target)
         {
@@ -1251,8 +1252,6 @@ public static PrefabType GetPrefabType(Object target)
             return PrefabType.PrefabInstance;
         }
 
-#pragma warning restore CS0618 // Type or member is obsolete
-
         // Called after prefab instances in the scene have been updated
         public delegate void PrefabInstanceUpdated(GameObject instance);
         public static PrefabInstanceUpdated prefabInstanceUpdated;
@@ -1328,7 +1327,7 @@ public static void UnpackPrefabInstance(GameObject root, PrefabUnpackMode unpack
             if (!IsPartOfNonAssetPrefabInstance(root))
                 throw new ArgumentException("UnpackPrefabInstance must be called with a Prefab instance.");
 
-            if (GetPrefabInstanceRootGameObject(root) != root)
+            if (!IsOutermostPrefabInstanceRoot(root))
                 throw new ArgumentException("UnpackPrefabInstance must be called with a root Prefab instance GameObject.");
 
             if (action == InteractionMode.UserAction)
@@ -1351,24 +1350,6 @@ public static void UnpackPrefabInstance(GameObject root, PrefabUnpackMode unpack
             }
         }
 
-        public static bool IsPartOfImmutablePrefab(Object gameObjectOrComponent)
-        {
-            if (IsPartOfModelPrefab(gameObjectOrComponent))
-                return true;
-
-            // If prefab instance, get the prefab asset.
-            if (!EditorUtility.IsPersistent(gameObjectOrComponent))
-                gameObjectOrComponent = GetCorrespondingObjectFromSource(gameObjectOrComponent);
-
-            string prefabAssetPath = AssetDatabase.GetAssetPath(gameObjectOrComponent);
-            bool isRootFolder, isReadonly;
-            bool validPath = AssetDatabase.GetAssetFolderInfo(prefabAssetPath, out isRootFolder, out isReadonly);
-            if (validPath && isReadonly)
-                return true;
-
-            return false;
-        }
-
         internal static bool HasInvalidComponent(Object gameObjectOrComponent)
         {
             if (gameObjectOrComponent == null)
diff --git a/Editor/Mono/ProjectBrowser.cs b/Editor/Mono/ProjectBrowser.cs
index 513ebb2d6e..fd04e054d5 100644
--- a/Editor/Mono/ProjectBrowser.cs
+++ b/Editor/Mono/ProjectBrowser.cs
@@ -2266,7 +2266,7 @@ void AssetLabelsDropDown()
             Rect r = GUILayoutUtility.GetRect(s_Styles.m_FilterByLabel, EditorStyles.toolbarButton);
             if (EditorGUI.DropdownButton(r, s_Styles.m_FilterByLabel, FocusType.Passive, EditorStyles.toolbarButton))
             {
-                PopupWindow.Show(r, new PopupList(m_AssetLabels), null, ShowMode.PopupMenuWithKeyboardFocus);
+                PopupWindow.Show(r, new PopupList(m_AssetLabels));
             }
         }
 
diff --git a/Editor/Mono/ProjectWindow/ProjectWindowUtil.cs b/Editor/Mono/ProjectWindow/ProjectWindowUtil.cs
index f1543afe72..9277fffd56 100644
--- a/Editor/Mono/ProjectWindow/ProjectWindowUtil.cs
+++ b/Editor/Mono/ProjectWindow/ProjectWindowUtil.cs
@@ -107,15 +107,6 @@ public override void Action(int instanceId, string pathName, string resourceFile
             }
         }
 
-        internal class DoCreatePrefab : EndNameEditAction
-        {
-            public override void Action(int instanceId, string pathName, string resourceFile)
-            {
-                Object o = PrefabUtility.CreateEmptyPrefab(pathName);
-                ProjectWindowUtil.ShowCreatedAsset(o);
-            }
-        }
-
         internal class DoCreatePrefabVariant : EndNameEditAction
         {
             public override void Action(int instanceId, string pathName, string resourceFile)
@@ -257,12 +248,6 @@ public static void CreateScene()
             StartNameEditingIfProjectWindowExists(0, ScriptableObject.CreateInstance<DoCreateScene>(), "New Scene.unity", EditorGUIUtility.FindTexture(typeof(SceneAsset)), null);
         }
 
-        // Create a prefab
-        public static void CreatePrefab()
-        {
-            StartNameEditingIfProjectWindowExists(0, ScriptableObject.CreateInstance<DoCreatePrefab>(), "New Prefab.prefab", EditorGUIUtility.IconContent("Prefab Icon").image as Texture2D, null);
-        }
-
         [MenuItem("Assets/Create/Prefab Variant", true)]
         static bool CreatePrefabVariantValidation()
         {
diff --git a/Editor/Mono/SceneHierarchy.cs b/Editor/Mono/SceneHierarchy.cs
index dec6f48fed..1f5e4ed5a8 100644
--- a/Editor/Mono/SceneHierarchy.cs
+++ b/Editor/Mono/SceneHierarchy.cs
@@ -485,8 +485,6 @@ public virtual void OnEnable()
             EditorSceneManager.newSceneCreated += OnSceneCreated;
             EditorSceneManager.sceneOpened += OnSceneOpened;
 
-            DoPingRequest();
-
             m_AllowAlphaNumericalSort = EditorPrefs.GetBool("AllowAlphaNumericHierarchy", false) || !InternalEditorUtility.isHumanControllingUs; // Always allow alphasorting when running automated tests so we can test alpha sorting
             SetUpSortMethodLists();
 
@@ -495,6 +493,8 @@ public virtual void OnEnable()
 
             if (m_TreeViewKeyboardControlID == 0)
                 m_TreeViewKeyboardControlID = EditorGUIUtility.GetPermanentControlID();
+
+            DoPingRequest();
         }
 
         public virtual void OnDisable()
diff --git a/Editor/Mono/SceneHierarchyStageHandling.cs b/Editor/Mono/SceneHierarchyStageHandling.cs
index a633173992..b0dffebe74 100644
--- a/Editor/Mono/SceneHierarchyStageHandling.cs
+++ b/Editor/Mono/SceneHierarchyStageHandling.cs
@@ -105,8 +105,30 @@ void HandleFirstTimePrefabStageIsOpened(StageNavigationItem stage)
         {
             if (stage.isPrefabStage && GetStoredHierarchyState(m_SceneHierarchyWindow, stage) == null)
             {
-                var visibleRootID = stage.prefabStage.prefabContentsRoot.GetInstanceID();
-                m_SceneHierarchy.SetExpandedRecursive(visibleRootID, true);
+                SetDefaultExpandedStateForOpenedPrefab(stage.prefabStage.prefabContentsRoot);
+            }
+        }
+
+        void SetDefaultExpandedStateForOpenedPrefab(GameObject root)
+        {
+            var expandedIDs = new List<int>();
+            AddParentsBelowButIgnoreNestedPrefabsRecursive(root.transform, expandedIDs);
+            expandedIDs.Sort();
+            m_SceneHierarchy.treeViewState.expandedIDs = expandedIDs;
+        }
+
+        void AddParentsBelowButIgnoreNestedPrefabsRecursive(Transform transform, List<int> gameObjectInstanceIDs)
+        {
+            gameObjectInstanceIDs.Add(transform.gameObject.GetInstanceID());
+
+            int count = transform.childCount;
+            for (int i = 0; i < count; ++i)
+            {
+                var child = transform.GetChild(i);
+                if (child.childCount > 0 && !PrefabUtility.IsAnyPrefabInstanceRoot(child.gameObject))
+                {
+                    AddParentsBelowButIgnoreNestedPrefabsRecursive(child, gameObjectInstanceIDs);
+                }
             }
         }
 
diff --git a/Editor/Mono/SceneManagement/StageManager/PrefabStage/PrefabStage.cs b/Editor/Mono/SceneManagement/StageManager/PrefabStage/PrefabStage.cs
index 3bee757397..6de9a6e44c 100644
--- a/Editor/Mono/SceneManagement/StageManager/PrefabStage/PrefabStage.cs
+++ b/Editor/Mono/SceneManagement/StageManager/PrefabStage/PrefabStage.cs
@@ -61,7 +61,7 @@ public GameObject prefabContentsRoot
             get
             {
                 if (m_PrefabContentsRoot == null)
-                    throw new InvalidOperationException("Requesting 'prefabContentsRoot' from Awake and OnEnable are not supported"); // The preview scene is not fully loaded when we call Awake and OnEnable on user scripts
+                    throw new InvalidOperationException("Requesting 'prefabContentsRoot' from Awake and OnEnable are not supported"); // The prefab stage's m_PrefabContentsRoot is not yet set when we call Awake and OnEnable on user scripts when loading a prefab
                 return m_PrefabContentsRoot;
             }
         }
@@ -261,7 +261,7 @@ bool isTextFieldCaretShowing
 
         bool readyToAutoSave
         {
-            get { return m_PrefabContentsRoot != null && HasSceneBeenModified() && GUIUtility.hotControl == 0 && !isTextFieldCaretShowing; }
+            get { return m_PrefabContentsRoot != null && HasSceneBeenModified() && GUIUtility.hotControl == 0 && !isTextFieldCaretShowing && !EditorApplication.isCompiling; }
         }
 
         void HandleAutoSave()
@@ -313,11 +313,15 @@ internal void SavePrefab()
             if (prefabSaving != null)
                 prefabSaving(m_PrefabContentsRoot);
 
-            ClearDirtiness();
-            PrefabUtility.SaveAsPrefabAsset(m_PrefabContentsRoot, m_PrefabAssetPath);
+            var prefabAssetRoot = PrefabUtility.SaveAsPrefabAsset(m_PrefabContentsRoot, m_PrefabAssetPath);
 
-            if (prefabSaved != null)
-                prefabSaved(m_PrefabContentsRoot);
+            if (prefabAssetRoot != null)
+            {
+                ClearDirtiness();
+
+                if (prefabSaved != null)
+                    prefabSaved(m_PrefabContentsRoot);
+            }
 
             if (SceneHierarchy.s_DebugPrefabStage)
                 Debug.Log("SAVE PREFAB ended");
@@ -393,32 +397,26 @@ internal bool SaveAsNewPrefabWithSavePanel()
         // Returns true if prefab was saved.
         internal bool SavePrefabWithVersionControlDialogAndRenameDialog()
         {
-            Assert.IsTrue(m_PrefabContentsRoot != null, "We should have a valid m_PrefabContentsRoot when saving to prefab asset");
-            bool editablePrefab = !AnimationMode.InAnimationMode();
-
-            //bool editablePrefab = UnityEditor.VersionControl.Provider.PromptAndCheckoutIfNeeded(
-            //        new string[] {context.assetPath},
-            //        "The version control requires you to check out the prefab before applying changes.");
-
-            if (editablePrefab)
+            if (m_PrefabContentsRoot == null)
             {
-                if (!PrefabUtility.PromptAndCheckoutPrefabIfNeeded(m_PrefabAssetPath, PrefabUtility.SaveVerb.Save))
-                {
-                    // If user doesn't want to check out prefab asset, or it cannot be,
-                    // it doesn't make sense to keep auto save on.
-                    m_TemporarilyDisableAutoSave = true;
-                    return false;
-                }
-
-                bool showCancelButton = !autoSave;
-                if (!CheckRenamedPrefabRootWhenSaving(showCancelButton))
-                    return false;
+                Debug.LogError("We should have a valid m_PrefabContentsRoot when saving to prefab asset");
+                return false;
+            }
 
-                SavePrefab();
-                return true;
+            if (!PrefabUtility.PromptAndCheckoutPrefabIfNeeded(m_PrefabAssetPath, PrefabUtility.SaveVerb.Save))
+            {
+                // If user doesn't want to check out prefab asset, or it cannot be,
+                // it doesn't make sense to keep auto save on.
+                m_TemporarilyDisableAutoSave = true;
+                return false;
             }
 
-            return false;
+            bool showCancelButton = !autoSave;
+            if (!CheckRenamedPrefabRootWhenSaving(showCancelButton))
+                return false;
+
+            SavePrefab();
+            return true;
         }
 
         // Returns true if we should continue saving
diff --git a/Editor/Mono/SceneModeWindows/DefaultLightingExplorerExtension.cs b/Editor/Mono/SceneModeWindows/DefaultLightingExplorerExtension.cs
index b3f4b6ffa8..c546825ccd 100644
--- a/Editor/Mono/SceneModeWindows/DefaultLightingExplorerExtension.cs
+++ b/Editor/Mono/SceneModeWindows/DefaultLightingExplorerExtension.cs
@@ -14,7 +14,7 @@ private static class Styles
             public static readonly GUIContent[] ProjectionStrings = { EditorGUIUtility.TrTextContent("Infinite"), EditorGUIUtility.TrTextContent("Box") };
             public static readonly GUIContent[] LightmapEmissiveStrings = { EditorGUIUtility.TrTextContent("Realtime"), EditorGUIUtility.TrTextContent("Baked") };
             public static readonly GUIContent Name = EditorGUIUtility.TrTextContent("Name");
-            public static readonly GUIContent On = EditorGUIUtility.TrTextContent("On");
+            public static readonly GUIContent Enabled = EditorGUIUtility.TrTextContent("Enabled");
             public static readonly GUIContent Type = EditorGUIUtility.TrTextContent("Type");
             public static readonly GUIContent Shape = EditorGUIUtility.TrTextContent("Shape");
             public static readonly GUIContent Mode = EditorGUIUtility.TrTextContent("Mode");
@@ -69,8 +69,8 @@ protected virtual LightingExplorerTableColumn[] GetLightColumns()
         {
             return new[]
             {
-                new LightingExplorerTableColumn(LightingExplorerTableColumn.DataType.Name, Styles.Name, null, 200), // 0: Name
-                new LightingExplorerTableColumn(LightingExplorerTableColumn.DataType.Checkbox, Styles.On, "m_Enabled", 25), // 1: Enabled
+                new LightingExplorerTableColumn(LightingExplorerTableColumn.DataType.Checkbox, Styles.Enabled, "m_Enabled", 50), // 0: Enabled
+                new LightingExplorerTableColumn(LightingExplorerTableColumn.DataType.Name, Styles.Name, null, 200), // 1: Name
                 new LightingExplorerTableColumn(LightingExplorerTableColumn.DataType.Enum, Styles.Type, "m_Type", 120, (r, prop, dep) =>
                 {
                     // To the user, we will only display it as a area light, but under the hood, we have Rectangle and Disc. This is not to confuse people
@@ -168,8 +168,8 @@ protected virtual LightingExplorerTableColumn[] GetReflectionProbeColumns()
         {
             return new[]
             {
-                new LightingExplorerTableColumn(LightingExplorerTableColumn.DataType.Name, Styles.Name, null, 200),  // 0: Name
-                new LightingExplorerTableColumn(LightingExplorerTableColumn.DataType.Checkbox, Styles.On, "m_Enabled", 25), // 1: Enabled
+                new LightingExplorerTableColumn(LightingExplorerTableColumn.DataType.Checkbox, Styles.Enabled, "m_Enabled", 50), // 0: Enabled
+                new LightingExplorerTableColumn(LightingExplorerTableColumn.DataType.Name, Styles.Name, null, 200),  // 1: Name
                 new LightingExplorerTableColumn(LightingExplorerTableColumn.DataType.Int, Styles.Mode, "m_Mode", 70, (r, prop, dep) =>
                 {
                     EditorGUI.IntPopup(r, prop, ReflectionProbeEditor.Styles.reflectionProbeMode, ReflectionProbeEditor.Styles.reflectionProbeModeValues, GUIContent.none);
@@ -195,8 +195,8 @@ protected virtual LightingExplorerTableColumn[] GetLightProbeColumns()
         {
             return new[]
             {
-                new LightingExplorerTableColumn(LightingExplorerTableColumn.DataType.Name, Styles.Name, null, 200), // 0: Name
-                new LightingExplorerTableColumn(LightingExplorerTableColumn.DataType.Checkbox, Styles.On, "m_Enabled", 25), // 1: Enabled
+                new LightingExplorerTableColumn(LightingExplorerTableColumn.DataType.Checkbox, Styles.Enabled, "m_Enabled", 50), // 0: Enabled
+                new LightingExplorerTableColumn(LightingExplorerTableColumn.DataType.Name, Styles.Name, null, 200), // 1: Name
             };
         }
 
diff --git a/Editor/Mono/SceneModeWindows/LightingWindowBakeSettings.cs b/Editor/Mono/SceneModeWindows/LightingWindowBakeSettings.cs
index 79ac29a750..64c5a47251 100644
--- a/Editor/Mono/SceneModeWindows/LightingWindowBakeSettings.cs
+++ b/Editor/Mono/SceneModeWindows/LightingWindowBakeSettings.cs
@@ -71,7 +71,6 @@ internal class LightingWindowBakeSettings
         SerializedProperty m_PVRFilteringAtrousPositionSigmaAO;
 
         SerializedProperty  m_BounceScale;
-        SerializedProperty  m_UpdateThreshold;
 
         static bool PlayerHasSM20Support()
         {
@@ -131,7 +130,6 @@ private void InitSettings()
 
             //dev debug properties
             m_BounceScale = so.FindProperty("m_GISettings.m_BounceScale");
-            m_UpdateThreshold = so.FindProperty("m_GISettings.m_TemporalCoherenceThreshold");
         }
 
         public void OnEnable()
@@ -351,7 +349,6 @@ public void DeveloperBuildSettingsGUI()
             Lightmapping.filterMode = (FilterMode)EditorGUILayout.EnumPopup(EditorGUIUtility.TempContent("Filter Mode"), Lightmapping.filterMode);
 
             EditorGUILayout.Slider(m_BounceScale, 0.0f, 10.0f, Styles.BounceScale);
-            EditorGUILayout.Slider(m_UpdateThreshold, 0.0f, 1.0f, Styles.UpdateThreshold);
 
             if (GUILayout.Button("Clear disk cache", GUILayout.Width(LightingWindow.kButtonWidth)))
             {
@@ -371,6 +368,16 @@ public void DeveloperBuildSettingsGUI()
                 DynamicGI.UpdateEnvironment();
         }
 
+        private void ClampFilterType(SerializedProperty filter)
+        {
+            if (LightmapEditorSettings.lightmapper == LightmapEditorSettings.Lightmapper.ProgressiveGPU)
+            {
+                // Force unsupported A-Trous filter back to Gaussian.
+                if (filter.intValue == 1)
+                    filter.intValue = 0;
+            }
+        }
+
         void GeneralLightmapSettingsGUI()
         {
             bool bakedGISupported = SupportedRenderingFeatures.IsLightmapBakeTypeSupported(LightmapBakeType.Baked);
@@ -453,7 +460,16 @@ void GeneralLightmapSettingsGUI()
                                 {
                                     EditorGUI.indentLevel++;
 
-                                    EditorGUILayout.PropertyField(m_PVRFilterTypeDirect, Styles.PVRFilterTypeDirect);
+                                    // TODO(RadeonRays): Hiding A-trous until it is implemented.
+                                    var filterOptions = new[] { EditorGUIUtility.TextContent("Gaussian"), EditorGUIUtility.TextContent("None") };
+                                    var filterInts = new[] { 0, 2 };
+
+                                    ClampFilterType(m_PVRFilterTypeDirect);
+                                    if (LightmapEditorSettings.lightmapper == LightmapEditorSettings.Lightmapper.ProgressiveGPU)
+                                        EditorGUILayout.IntPopup(m_PVRFilterTypeDirect, filterOptions, filterInts, Styles.PVRFilterTypeDirect);
+                                    else
+                                        EditorGUILayout.PropertyField(m_PVRFilterTypeDirect, Styles.PVRFilterTypeDirect);
+
                                     DrawFilterSettingField(m_PVRFilteringGaussRadiusDirect,
                                         m_PVRFilteringAtrousPositionSigmaDirect,
                                         Styles.PVRFilteringGaussRadiusDirect,
@@ -462,7 +478,11 @@ void GeneralLightmapSettingsGUI()
 
                                     EditorGUILayout.Space();
 
-                                    EditorGUILayout.PropertyField(m_PVRFilterTypeIndirect, Styles.PVRFilterTypeIndirect);
+                                    if (LightmapEditorSettings.lightmapper == LightmapEditorSettings.Lightmapper.ProgressiveGPU)
+                                        EditorGUILayout.IntPopup(m_PVRFilterTypeIndirect, filterOptions, filterInts, Styles.PVRFilterTypeIndirect);
+                                    else
+                                        EditorGUILayout.PropertyField(m_PVRFilterTypeIndirect, Styles.PVRFilterTypeIndirect);
+                                    ClampFilterType(m_PVRFilterTypeIndirect);
                                     DrawFilterSettingField(m_PVRFilteringGaussRadiusIndirect,
                                         m_PVRFilteringAtrousPositionSigmaIndirect,
                                         Styles.PVRFilteringGaussRadiusIndirect,
@@ -472,8 +492,11 @@ void GeneralLightmapSettingsGUI()
                                     using (new EditorGUI.DisabledScope(!m_AmbientOcclusion.boolValue))
                                     {
                                         EditorGUILayout.Space();
-
-                                        EditorGUILayout.PropertyField(m_PVRFilterTypeAO, Styles.PVRFilterTypeAO);
+                                        if (LightmapEditorSettings.lightmapper == LightmapEditorSettings.Lightmapper.ProgressiveGPU)
+                                            EditorGUILayout.IntPopup(m_PVRFilterTypeAO, filterOptions, filterInts, Styles.PVRFilterTypeAO);
+                                        else
+                                            EditorGUILayout.PropertyField(m_PVRFilterTypeAO, Styles.PVRFilterTypeAO);
+                                        ClampFilterType(m_PVRFilterTypeAO);
                                         DrawFilterSettingField(m_PVRFilteringGaussRadiusAO,
                                             m_PVRFilteringAtrousPositionSigmaAO,
                                             Styles.PVRFilteringGaussRadiusAO, Styles.PVRFilteringAtrousPositionSigmaAO,
diff --git a/Editor/Mono/SceneView/SceneView.cs b/Editor/Mono/SceneView/SceneView.cs
index ab9c61444e..7adc6e7d02 100644
--- a/Editor/Mono/SceneView/SceneView.cs
+++ b/Editor/Mono/SceneView/SceneView.cs
@@ -741,7 +741,7 @@ void ToolbarDisplayStateGUI()
             if (EditorGUI.DropdownButton(modeRect, modeContent, FocusType.Passive, EditorStyles.toolbarDropDown))
             {
                 Rect rect = GUILayoutUtility.topLevel.GetLast();
-                PopupWindow.Show(rect, new SceneRenderModeWindow(this), null, ShowMode.PopupMenuWithKeyboardFocus);
+                PopupWindow.Show(rect, new SceneRenderModeWindow(this));
                 GUIUtility.ExitGUI();
             }
 
@@ -768,7 +768,7 @@ void ToolbarDisplayStateGUI()
             if (EditorGUI.DropdownButton(fxRightRect, GUIContent.none, FocusType.Passive, GUIStyle.none))
             {
                 Rect rect = GUILayoutUtility.topLevel.GetLast();
-                PopupWindow.Show(rect, new SceneFXWindow(this), null, ShowMode.PopupMenuWithKeyboardFocus);
+                PopupWindow.Show(rect, new SceneFXWindow(this));
                 GUIUtility.ExitGUI();
             }
 
diff --git a/Editor/Mono/Scripting/Compilers/UWPReferences.cs b/Editor/Mono/Scripting/Compilers/UWPReferences.cs
index f057f616bf..da1105c3a5 100644
--- a/Editor/Mono/Scripting/Compilers/UWPReferences.cs
+++ b/Editor/Mono/Scripting/Compilers/UWPReferences.cs
@@ -174,15 +174,11 @@ public static IEnumerable<KeyValuePair<UWPSDK, IEnumerable<KeyValuePair<string,
                                 foreach (XElement previousPlatformElement in previousPlatformsDocument.Element(xn + "PreviousPlatforms").Elements(xn + "ApplicationPlatform"))
                                 {
                                     var previousVersion = previousPlatformElement.Attribute("version").Value;
-                                    var isDefault = false;
+                                    bool isDefault;
 
-                                    try
+                                    if (!bool.TryParse(previousPlatformElement.Attribute("IsDefaultFallback").Value, out isDefault))
                                     {
-                                        isDefault = bool.Parse(previousPlatformElement.Attribute("IsDefaultFallback").Value);
-                                    }
-                                    catch
-                                    {
-                                        // Ignore exception. The IsDefaultFallback attribute isn't present. This is OK.
+                                        isDefault = false;
                                     }
 
                                     previousVersions.Add(previousVersion, new PreviousSDKVersion(previousVersion, isDefault));
diff --git a/Editor/Mono/Scripting/ScriptCompilation/EditorCompilation.cs b/Editor/Mono/Scripting/ScriptCompilation/EditorCompilation.cs
index b607729175..d9ea366d92 100644
--- a/Editor/Mono/Scripting/ScriptCompilation/EditorCompilation.cs
+++ b/Editor/Mono/Scripting/ScriptCompilation/EditorCompilation.cs
@@ -487,7 +487,8 @@ void CheckCyclicAssemblyReferences()
             }
         }
 
-        Exception[] UpdateCustomTargetAssemblies()
+        public static Exception[] UpdateCustomScriptAssemblies(CustomScriptAssembly[] customScriptAssemblies,
+            PackageAssembly[] packageAssemblies)
         {
             var exceptions = new List<Exception>();
 
@@ -495,14 +496,14 @@ Exception[] UpdateCustomTargetAssemblies()
             {
                 try
                 {
-                    if (m_PackageAssemblies != null && !assembly.PackageAssembly.HasValue)
+                    if (packageAssemblies != null && !assembly.PackageAssembly.HasValue)
                     {
                         var pathPrefix = assembly.PathPrefix.ToLowerInvariant();
 
-                        foreach (var packageAssembly in m_PackageAssemblies)
+                        foreach (var packageAssembly in packageAssemblies)
                         {
-                            var lower = AssetPath.ReplaceSeparators(packageAssembly.DirectoryPath).ToLowerInvariant();
-                            if (pathPrefix.StartsWith(lower))
+                            var lower = AssetPath.ReplaceSeparators(packageAssembly.DirectoryPath + AssetPath.Separator).ToLowerInvariant();
+                            if (pathPrefix.StartsWith(lower, StringComparison.Ordinal))
                             {
                                 assembly.PackageAssembly = packageAssembly;
                                 break;
@@ -521,11 +522,22 @@ Exception[] UpdateCustomTargetAssemblies()
                 }
                 catch (Exception e)
                 {
-                    SetCompilationSetupErrorFlags(CompilationSetupErrorFlags.loadError);
                     exceptions.Add(e);
                 }
             }
 
+            return exceptions.ToArray();
+        }
+
+        Exception[] UpdateCustomTargetAssemblies()
+        {
+            var exceptions = UpdateCustomScriptAssemblies(customScriptAssemblies, m_PackageAssemblies);
+
+            if (exceptions.Length > 0)
+            {
+                SetCompilationSetupErrorFlags(CompilationSetupErrorFlags.loadError);
+            }
+
             customTargetAssemblies = EditorBuildRules.CreateTargetAssemblies(customScriptAssemblies, precompiledAssemblies);
             ClearCompilationSetupErrorFlags(CompilationSetupErrorFlags.cyclicReferences);
 
@@ -533,7 +545,7 @@ Exception[] UpdateCustomTargetAssemblies()
             // customTargetAssemblies being updated.
             UpdateDirtyTargetAssemblies();
 
-            return exceptions.ToArray();
+            return exceptions;
         }
 
         void UpdateDirtyTargetAssemblies()
diff --git a/Editor/Mono/Scripting/ScriptCompilation/EditorScriptCompilationOptions.cs b/Editor/Mono/Scripting/ScriptCompilation/EditorScriptCompilationOptions.cs
index 54d00b3510..c2cc1d0136 100644
--- a/Editor/Mono/Scripting/ScriptCompilation/EditorScriptCompilationOptions.cs
+++ b/Editor/Mono/Scripting/ScriptCompilation/EditorScriptCompilationOptions.cs
@@ -17,6 +17,7 @@ enum EditorScriptCompilationOptions
         BuildingForIl2Cpp = 1 << 3,
         BuildingWithAsserts = 1 << 4,
         BuildingIncludingTestAssemblies = 1 << 5,
-        BuildingPredefinedAssembliesAllowUnsafeCode = (1 << 6)
+        BuildingPredefinedAssembliesAllowUnsafeCode = (1 << 6),
+        BuildingForHeadlessPlayer = 1 << 7
     };
 }
diff --git a/Editor/Mono/TooltipView/TooltipView.cs b/Editor/Mono/TooltipView/TooltipView.cs
index 4a9b6242c8..bc3f53b210 100644
--- a/Editor/Mono/TooltipView/TooltipView.cs
+++ b/Editor/Mono/TooltipView/TooltipView.cs
@@ -66,7 +66,7 @@ void Setup(string tooltip, Rect rect)
 
             position = new Rect(0, 0, m_optimalSize.x, m_optimalSize.y);
 
-            window.ShowPopup();
+            window.ShowTooltip();
             window.SetAlpha(1.0f);
             s_guiView.mouseRayInvisible = true;
 
diff --git a/Editor/Mono/VisualStudioIntegration/SolutionSynchronizer.cs b/Editor/Mono/VisualStudioIntegration/SolutionSynchronizer.cs
index 5392398c9f..ec051304c7 100644
--- a/Editor/Mono/VisualStudioIntegration/SolutionSynchronizer.cs
+++ b/Editor/Mono/VisualStudioIntegration/SolutionSynchronizer.cs
@@ -205,6 +205,12 @@ private bool ShouldSyncOnReimportedAsset(string asset)
 
         public void Sync()
         {
+            // Do not sync solution until all Unity extensions are registered and initialized.
+            // Otherwise Unity might emit errors when VSTU tries to generate the solution and
+            // get all managed extensions, which not yet initialized.
+            if (!InternalEditorUtility.IsUnityExtensionsInitialized())
+                return;
+
             SetupProjectSupportedExtensions();
 
             bool externalCodeAlreadyGeneratedProjects = AssetPostprocessingInternal.OnPreGeneratingCSProjectFiles();
diff --git a/Modules/AssetPipelineEditor/ImportSettings/AssetImporterTabbedEditor.cs b/Modules/AssetPipelineEditor/ImportSettings/AssetImporterTabbedEditor.cs
index e3ec3ddce3..129af826f3 100644
--- a/Modules/AssetPipelineEditor/ImportSettings/AssetImporterTabbedEditor.cs
+++ b/Modules/AssetPipelineEditor/ImportSettings/AssetImporterTabbedEditor.cs
@@ -88,6 +88,8 @@ public override void OnInspectorGUI()
             // the activeTab can get destroyed when opening particular sub-editors (such as the Avatar configuration editor on the Rig tab)
             if (activeTab != null)
             {
+                GUILayout.Space(EditorGUI.kSpacing);
+
                 activeTab.OnInspectorGUI();
             }
 
diff --git a/Modules/GraphViewEditor/Manipulators/SelectionDragger.cs b/Modules/GraphViewEditor/Manipulators/SelectionDragger.cs
index 790fb52601..56e112b8af 100644
--- a/Modules/GraphViewEditor/Manipulators/SelectionDragger.cs
+++ b/Modules/GraphViewEditor/Manipulators/SelectionDragger.cs
@@ -453,6 +453,8 @@ void MoveElement(GraphElement element, Rect originalPos)
                         var graphView = target as GraphView;
                         if (graphView != null && graphView.graphViewChanged != null)
                         {
+                            KeyValuePair<GraphElement, OriginalPos> firstPos = m_OriginalPos.First();
+                            m_GraphViewChange.moveDelta = firstPos.Key.GetPosition().position - firstPos.Value.pos.position;
                             graphView.graphViewChanged(m_GraphViewChange);
                         }
                     }
diff --git a/Modules/GraphViewEditor/Views/GraphView.cs b/Modules/GraphViewEditor/Views/GraphView.cs
index e65244ab2c..a22ce0220b 100644
--- a/Modules/GraphViewEditor/Views/GraphView.cs
+++ b/Modules/GraphViewEditor/Views/GraphView.cs
@@ -44,6 +44,7 @@ public struct GraphViewChange
 
         // Operations Completed
         public List<GraphElement> movedElements;
+        public Vector2 moveDelta;
     }
 
     public struct NodeCreationContext
diff --git a/Modules/GridEditor/Managed/GridEditorUtility.cs b/Modules/GridEditor/Managed/GridEditorUtility.cs
index 7516832bc6..59891615e0 100644
--- a/Modules/GridEditor/Managed/GridEditorUtility.cs
+++ b/Modules/GridEditor/Managed/GridEditorUtility.cs
@@ -216,10 +216,10 @@ public static void DrawGridMarquee(GridLayout gridLayout, BoundsInt area, Color
 
                     Vector3[] cellLocals =
                     {
-                        gridLayout.CellToLocal(new Vector3Int(area.xMin, area.yMin, 0)),
-                        gridLayout.CellToLocalInterpolated(new Vector3(area.xMax - 1 + cellGap.x, area.yMin, 0)),
-                        gridLayout.CellToLocalInterpolated(new Vector3(area.xMax - 1 + cellGap.x, area.yMax - 1  + cellGap.y, 0)),
-                        gridLayout.CellToLocalInterpolated(new Vector3(area.xMin, area.yMax - 1 + cellGap.y, 0))
+                        gridLayout.CellToLocal(new Vector3Int(area.xMin, area.yMin, area.zMin)),
+                        gridLayout.CellToLocalInterpolated(new Vector3(area.xMax - 1 + cellGap.x, area.yMin, area.zMin)),
+                        gridLayout.CellToLocalInterpolated(new Vector3(area.xMax - 1 + cellGap.x, area.yMax - 1  + cellGap.y, area.zMin)),
+                        gridLayout.CellToLocalInterpolated(new Vector3(area.xMin, area.yMax - 1 + cellGap.y, area.zMin))
                     };
 
                     HandleUtility.ApplyWireMaterial();
@@ -252,34 +252,34 @@ public static void DrawSelectedHexGridArea(GridLayout gridLayout, BoundsInt area
             int right = horizontalCount;
             Vector3[] cellOffset =
             {
-                Grid.Swizzle(gridLayout.cellSwizzle, new Vector3(0, gridLayout.cellSize.y / 2, 0)),
-                Grid.Swizzle(gridLayout.cellSwizzle, new Vector3(gridLayout.cellSize.x / 2, gridLayout.cellSize.y / 4, 0)),
-                Grid.Swizzle(gridLayout.cellSwizzle, new Vector3(gridLayout.cellSize.x / 2, -gridLayout.cellSize.y / 4, 0)),
-                Grid.Swizzle(gridLayout.cellSwizzle, new Vector3(0, -gridLayout.cellSize.y / 2, 0)),
-                Grid.Swizzle(gridLayout.cellSwizzle, new Vector3(-gridLayout.cellSize.x / 2, -gridLayout.cellSize.y / 4, 0)),
-                Grid.Swizzle(gridLayout.cellSwizzle, new Vector3(-gridLayout.cellSize.x / 2, gridLayout.cellSize.y / 4, 0))
+                Grid.Swizzle(gridLayout.cellSwizzle, new Vector3(0, gridLayout.cellSize.y / 2, area.zMin)),
+                Grid.Swizzle(gridLayout.cellSwizzle, new Vector3(gridLayout.cellSize.x / 2, gridLayout.cellSize.y / 4, area.zMin)),
+                Grid.Swizzle(gridLayout.cellSwizzle, new Vector3(gridLayout.cellSize.x / 2, -gridLayout.cellSize.y / 4, area.zMin)),
+                Grid.Swizzle(gridLayout.cellSwizzle, new Vector3(0, -gridLayout.cellSize.y / 2, area.zMin)),
+                Grid.Swizzle(gridLayout.cellSwizzle, new Vector3(-gridLayout.cellSize.x / 2, -gridLayout.cellSize.y / 4, area.zMin)),
+                Grid.Swizzle(gridLayout.cellSwizzle, new Vector3(-gridLayout.cellSize.x / 2, gridLayout.cellSize.y / 4, area.zMin))
             };
             // Fill Top and Bottom Vertices
             for (int x = area.min.x; x < area.max.x; x++)
             {
-                cellLocals[bottom++] = gridLayout.CellToLocal(new Vector3Int(x, area.min.y, 0)) + cellOffset[4];
-                cellLocals[bottom++] = gridLayout.CellToLocal(new Vector3Int(x, area.min.y, 0)) + cellOffset[3];
-                cellLocals[top--] = gridLayout.CellToLocal(new Vector3Int(x, area.max.y - 1, 0)) + cellOffset[0];
-                cellLocals[top--] = gridLayout.CellToLocal(new Vector3Int(x, area.max.y - 1, 0)) + cellOffset[1];
+                cellLocals[bottom++] = gridLayout.CellToLocal(new Vector3Int(x, area.min.y, area.zMin)) + cellOffset[4];
+                cellLocals[bottom++] = gridLayout.CellToLocal(new Vector3Int(x, area.min.y, area.zMin)) + cellOffset[3];
+                cellLocals[top--] = gridLayout.CellToLocal(new Vector3Int(x, area.max.y - 1, area.zMin)) + cellOffset[0];
+                cellLocals[top--] = gridLayout.CellToLocal(new Vector3Int(x, area.max.y - 1, area.zMin)) + cellOffset[1];
             }
             // Fill first Left and Right Vertices
-            cellLocals[left--] = gridLayout.CellToLocal(new Vector3Int(area.min.x, area.min.y, 0)) + cellOffset[5];
-            cellLocals[top--] = gridLayout.CellToLocal(new Vector3Int(area.max.x - 1, area.max.y - 1, 0)) + cellOffset[2];
+            cellLocals[left--] = gridLayout.CellToLocal(new Vector3Int(area.min.x, area.min.y, area.zMin)) + cellOffset[5];
+            cellLocals[top--] = gridLayout.CellToLocal(new Vector3Int(area.max.x - 1, area.max.y - 1, area.zMin)) + cellOffset[2];
             // Fill Left and Right Vertices
             for (int y = area.min.y + 1; y < area.max.y; y++)
             {
-                cellLocals[left--] = gridLayout.CellToLocal(new Vector3Int(area.min.x, y, 0)) + cellOffset[4];
-                cellLocals[left--] = gridLayout.CellToLocal(new Vector3Int(area.min.x, y, 0)) + cellOffset[5];
+                cellLocals[left--] = gridLayout.CellToLocal(new Vector3Int(area.min.x, y, area.zMin)) + cellOffset[4];
+                cellLocals[left--] = gridLayout.CellToLocal(new Vector3Int(area.min.x, y, area.zMin)) + cellOffset[5];
             }
             for (int y = area.min.y; y < (area.max.y - 1); y++)
             {
-                cellLocals[right++] = gridLayout.CellToLocal(new Vector3Int(area.max.x - 1, y, 0)) + cellOffset[2];
-                cellLocals[right++] = gridLayout.CellToLocal(new Vector3Int(area.max.x - 1, y, 0)) + cellOffset[1];
+                cellLocals[right++] = gridLayout.CellToLocal(new Vector3Int(area.max.x - 1, y, area.zMin)) + cellOffset[2];
+                cellLocals[right++] = gridLayout.CellToLocal(new Vector3Int(area.max.x - 1, y, area.zMin)) + cellOffset[1];
             }
             HandleUtility.ApplyWireMaterial();
             GL.PushMatrix();
diff --git a/Modules/IMGUI/GUILayout.cs b/Modules/IMGUI/GUILayout.cs
index 193026aef4..f204f4e28a 100644
--- a/Modules/IMGUI/GUILayout.cs
+++ b/Modules/IMGUI/GUILayout.cs
@@ -242,6 +242,11 @@ static public void FlexibleSpace()
 
             op.value = 10000;
             GUILayoutUtility.GetRect(0, 0, GUILayoutUtility.spaceStyle, op);
+
+            if (Event.current.type == EventType.Layout)
+            {
+                GUILayoutUtility.current.topLevel.entries[GUILayoutUtility.current.topLevel.entries.Count - 1].consideredForMargin = false;
+            }
         }
 
         public static void BeginHorizontal(params GUILayoutOption[] options) { BeginHorizontal(GUIContent.none, GUIStyle.none, options); }
diff --git a/Modules/ImageConversion/ScriptBindings/ImageConversion.bindings.cs b/Modules/ImageConversion/ScriptBindings/ImageConversion.bindings.cs
index 86ce9a075e..d5ea21ea9c 100644
--- a/Modules/ImageConversion/ScriptBindings/ImageConversion.bindings.cs
+++ b/Modules/ImageConversion/ScriptBindings/ImageConversion.bindings.cs
@@ -32,7 +32,7 @@ public static byte[] EncodeToEXR(this Texture2D tex)
         }
 
         [NativeMethod(Name = "ImageConversionBindings::LoadImage", IsFreeFunction = true)]
-        extern public static bool LoadImage(this Texture2D tex, byte[] data, bool markNonReadable);
+        extern public static bool LoadImage([NotNull] this Texture2D tex, byte[] data, bool markNonReadable);
         public static bool LoadImage(this Texture2D tex, byte[] data)
         {
             return LoadImage(tex, data, false);
diff --git a/Modules/ProfilerEditor/MemoryProfiler/MemorySnapshot.cs b/Modules/ProfilerEditor/MemoryProfiler/MemorySnapshot.cs
index c61d4a7ef8..3ca57653be 100644
--- a/Modules/ProfilerEditor/MemoryProfiler/MemorySnapshot.cs
+++ b/Modules/ProfilerEditor/MemoryProfiler/MemorySnapshot.cs
@@ -121,15 +121,21 @@ public UnityEngine.Profiling.Memory.Experimental.MetaData metadata
                 //     [opt: screenshot_width ]
                 //     [opt: screenshot_height ]
                 //     [opt: screenshot_format ]
+                var data = new UnityEngine.Profiling.Memory.Experimental.MetaData();
 
-                var metaData = new UnityEngine.Profiling.Memory.Experimental.MetaData();
+                if (array.Length == 0)
+                {
+                    data.content = "";
+                    data.platform = "";
+                    return data;
+                }
 
                 int offset = 0;
                 int dataLength = 0;
                 offset = ReadIntFromByteArray(array, offset, out dataLength);
-                offset = ReadStringFromByteArray(array, offset, dataLength, out metaData.content);
+                offset = ReadStringFromByteArray(array, offset, dataLength, out data.content);
                 offset = ReadIntFromByteArray(array, offset, out dataLength);
-                offset = ReadStringFromByteArray(array, offset, dataLength, out metaData.platform);
+                offset = ReadStringFromByteArray(array, offset, dataLength, out data.platform);
                 offset = ReadIntFromByteArray(array, offset, out dataLength);
 
                 if (dataLength > 0)
@@ -146,14 +152,14 @@ public UnityEngine.Profiling.Memory.Experimental.MetaData metadata
                     offset = ReadIntFromByteArray(array, offset, out height);
                     offset = ReadIntFromByteArray(array, offset, out format);
 
-                    metaData.screenshot = new Texture2D(width, height, (TextureFormat)format, false);
-                    metaData.screenshot.LoadRawTextureData(screenshot);
-                    metaData.screenshot.Apply();
+                    data.screenshot = new Texture2D(width, height, (TextureFormat)format, false);
+                    data.screenshot.LoadRawTextureData(screenshot);
+                    data.screenshot.Apply();
                 }
 
                 UnityEngine.Assertions.Assert.AreEqual(array.Length, offset);
 
-                return metaData;
+                return data;
             }
         }
 
diff --git a/Modules/ProfilerEditor/ProfilerWindow/NetworkDetailStats.cs b/Modules/ProfilerEditor/ProfilerWindow/NetworkDetailStats.cs
index 16ccf7806d..e8ba9d056b 100644
--- a/Modules/ProfilerEditor/ProfilerWindow/NetworkDetailStats.cs
+++ b/Modules/ProfilerEditor/ProfilerWindow/NetworkDetailStats.cs
@@ -119,8 +119,10 @@ public void NewProfilerTick(int tickId)
                 {
                     entry.NewProfilerTick(tickId);
                 }
+#pragma warning disable 618
                 NetworkTransport.SetPacketStat(0, MsgId, (int)totalIn, 1);
                 NetworkTransport.SetPacketStat(1, MsgId, (int)totalOut, 1);
+#pragma warning restore 618
                 totalIn = 0;
                 totalOut = 0;
             }
@@ -253,8 +255,10 @@ static public void ResetAll()
         {
             foreach (var detail in m_NetworkOperations.Values)
             {
+#pragma warning disable 618
                 NetworkTransport.SetPacketStat(0, detail.MsgId, 0, 1);
                 NetworkTransport.SetPacketStat(1, detail.MsgId, 0, 1);
+#pragma warning restore 618
             }
             m_NetworkOperations.Clear();
         }
diff --git a/Modules/ProfilerEditor/ProfilerWindow/ProfilerFrameHierarchyView.cs b/Modules/ProfilerEditor/ProfilerWindow/ProfilerFrameHierarchyView.cs
index 4850a99fb8..f7f1f41a83 100644
--- a/Modules/ProfilerEditor/ProfilerWindow/ProfilerFrameHierarchyView.cs
+++ b/Modules/ProfilerEditor/ProfilerWindow/ProfilerFrameHierarchyView.cs
@@ -7,6 +7,7 @@
 using System.Collections.Generic;
 using UnityEditor;
 using UnityEditor.IMGUI.Controls;
+using Unity.Profiling;
 
 namespace UnityEditorInternal.Profiling
 {
@@ -111,6 +112,8 @@ public bool sortedProfilerColumnAscending
         public delegate void SearchChangedCallback(string newSearch);
         public event SearchChangedCallback searchChanged;
 
+        static readonly ProfilerMarker m_DoGUIMarker = new ProfilerMarker(nameof(ProfilerFrameDataHierarchyView) + ".DoGUI");
+
         public ProfilerFrameDataHierarchyView()
         {
             m_Initialized = false;
@@ -275,70 +278,73 @@ static string GetProfilerColumnName(ProfilerColumn column)
 
         public void DoGUI(FrameDataView frameDataView)
         {
-            InitIfNeeded();
+            using (m_DoGUIMarker.Auto())
+            {
+                InitIfNeeded();
 
-            var collectingSamples = ProfilerDriver.enabled && (ProfilerDriver.profileEditor || EditorApplication.isPlaying);
-            var isSearchAllowed = string.IsNullOrEmpty(treeView.searchString) || !(collectingSamples && ProfilerDriver.deepProfiling);
+                var collectingSamples = ProfilerDriver.enabled && (ProfilerDriver.profileEditor || EditorApplication.isPlaying);
+                var isSearchAllowed = string.IsNullOrEmpty(treeView.searchString) || !(collectingSamples && ProfilerDriver.deepProfiling);
 
-            var isDataAvailable = frameDataView != null && frameDataView.IsValid();
-            if (isDataAvailable && isSearchAllowed)
-                if (isDataAvailable)
-                    m_TreeView.SetFrameDataView(frameDataView);
+                var isDataAvailable = frameDataView != null && frameDataView.IsValid();
+                if (isDataAvailable && isSearchAllowed)
+                    if (isDataAvailable)
+                        m_TreeView.SetFrameDataView(frameDataView);
 
-            var showDetailedView = isDataAvailable && m_DetailedViewType != DetailedViewType.None;
-            if (showDetailedView)
-                SplitterGUILayout.BeginHorizontalSplit(m_DetailedViewSpliterState);
+                var showDetailedView = isDataAvailable && m_DetailedViewType != DetailedViewType.None;
+                if (showDetailedView)
+                    SplitterGUILayout.BeginHorizontalSplit(m_DetailedViewSpliterState);
 
-            // Hierarchy view area
-            GUILayout.BeginVertical();
+                // Hierarchy view area
+                GUILayout.BeginVertical();
 
-            DrawToolbar(frameDataView, showDetailedView);
+                DrawToolbar(frameDataView, showDetailedView);
 
-            if (!isDataAvailable)
-            {
-                GUILayout.Label(BaseStyles.noData, BaseStyles.label);
-            }
-            else if (!isSearchAllowed)
-            {
-                GUILayout.Label(BaseStyles.disabledSearchText, BaseStyles.label);
-            }
-            else
-            {
-                var rect = GUILayoutUtility.GetRect(GUIContent.none, GUIStyle.none, GUILayout.ExpandHeight(true), GUILayout.ExpandHeight(true));
-                m_TreeView.OnGUI(rect);
-            }
+                if (!isDataAvailable)
+                {
+                    GUILayout.Label(BaseStyles.noData, BaseStyles.label);
+                }
+                else if (!isSearchAllowed)
+                {
+                    GUILayout.Label(BaseStyles.disabledSearchText, BaseStyles.label);
+                }
+                else
+                {
+                    var rect = GUILayoutUtility.GetRect(GUIContent.none, GUIStyle.none, GUILayout.ExpandHeight(true), GUILayout.ExpandHeight(true));
+                    m_TreeView.OnGUI(rect);
+                }
 
-            GUILayout.EndVertical();
+                GUILayout.EndVertical();
 
-            if (showDetailedView)
-            {
-                GUILayout.BeginVertical();
+                if (showDetailedView)
+                {
+                    GUILayout.BeginVertical();
 
-                // Detailed view area
-                EditorGUILayout.BeginHorizontal(BaseStyles.toolbar);
+                    // Detailed view area
+                    EditorGUILayout.BeginHorizontal(BaseStyles.toolbar);
 
-                DrawDetailedViewPopup();
-                GUILayout.FlexibleSpace();
+                    DrawDetailedViewPopup();
+                    GUILayout.FlexibleSpace();
 
-                DrawOptionsMenuPopup();
-                EditorGUILayout.EndHorizontal();
+                    DrawOptionsMenuPopup();
+                    EditorGUILayout.EndHorizontal();
 
-                switch (m_DetailedViewType)
-                {
-                    case DetailedViewType.Objects:
-                        detailedObjectsView.DoGUI(BaseStyles.header, frameDataView, m_TreeView.GetSelection());
-                        break;
-                    case DetailedViewType.CallersAndCallees:
-                        detailedCallsView.DoGUI(BaseStyles.header, frameDataView, m_TreeView.GetSelection());
-                        break;
-                }
+                    switch (m_DetailedViewType)
+                    {
+                        case DetailedViewType.Objects:
+                            detailedObjectsView.DoGUI(BaseStyles.header, frameDataView, m_TreeView.GetSelection());
+                            break;
+                        case DetailedViewType.CallersAndCallees:
+                            detailedCallsView.DoGUI(BaseStyles.header, frameDataView, m_TreeView.GetSelection());
+                            break;
+                    }
 
-                GUILayout.EndVertical();
+                    GUILayout.EndVertical();
 
-                SplitterGUILayout.EndHorizontalSplit();
-            }
+                    SplitterGUILayout.EndHorizontalSplit();
+                }
 
-            HandleKeyboardEvents();
+                HandleKeyboardEvents();
+            }
         }
 
         void DrawSearchBar()
diff --git a/Modules/ProfilerEditor/ProfilerWindow/ProfilerTimelineGUI.cs b/Modules/ProfilerEditor/ProfilerWindow/ProfilerTimelineGUI.cs
index 9d60438ccd..ee29b6a242 100644
--- a/Modules/ProfilerEditor/ProfilerWindow/ProfilerTimelineGUI.cs
+++ b/Modules/ProfilerEditor/ProfilerWindow/ProfilerTimelineGUI.cs
@@ -9,6 +9,7 @@
 using UnityEditorInternal.Profiling;
 using Object = UnityEngine.Object;
 using UnityEditor.AnimatedValues;
+using Unity.Profiling;
 
 namespace UnityEditorInternal
 {
@@ -36,12 +37,13 @@ internal class ThreadInfo
             public int threadIndex;
             public string name;
             public bool alive;
-            public int maxDepth = 1;
-            public ThreadInfo(string name, int threadIndex, int linesToDisplay)
+            public int maxDepth;
+            public ThreadInfo(string name, int threadIndex, int maxDepth, int linesToDisplay)
             {
                 this.name = name;
                 this.threadIndex = threadIndex;
                 this.linesToDisplay = linesToDisplay;
+                this.maxDepth = Mathf.Max(1, maxDepth);
             }
         }
 
@@ -227,6 +229,8 @@ struct RangeSelectionInfo
 
         RangeSelectionInfo m_RangeSelection = new RangeSelectionInfo();
 
+        static readonly ProfilerMarker m_DoGUIMarker = new ProfilerMarker(nameof(ProfilerTimelineGUI) + ".DoGUI");
+
         public ProfilerTimelineGUI(IProfilerWindowController window)
         {
             m_Window = window;
@@ -265,43 +269,21 @@ private void UpdateGroupAndThreadInfo(ref ProfilerFrameDataIterator iter, int fr
                 ThreadInfo thread = threads.Find(t => t.threadIndex == i);
                 if (thread == null)
                 {
-                    thread = new ThreadInfo(iter.GetThreadName(), i, group.defaultLineCountPerThread);
+                    // ProfilerFrameDataIterator.maxDepth includes the thread sample which is not getting displayed, so we store it at -1 for all intents and purposes
+                    thread = new ThreadInfo(iter.GetThreadName(), i, iter.maxDepth - 1, group.defaultLineCountPerThread);
                     // the main thread gets double the size
                     if (i == 0)
                         thread.linesToDisplay *= 2;
 
                     group.threads.Add(thread);
                 }
-                thread.alive = true;
-            }
-
-            if (m_LastSelectedFrameID != frameIndex)
-            {
-                foreach (var group in m_Groups)
+                else if (m_LastSelectedFrameID != frameIndex)
                 {
-                    foreach (var thread in group.threads)
-                    {
-                        thread.maxDepth = GetThreadMaxDepth(thread, frameIndex);
-                    }
-                }
-                m_LastSelectedFrameID = frameIndex;
-            }
-        }
-
-        int GetThreadMaxDepth(ThreadInfo thread, int frame)
-        {
-            int maxDepth = 1;
-            using (var iter = new ProfilerFrameDataIterator())
-            {
-                iter.SetRoot(frame, thread.threadIndex);
-
-                while (iter.Next(true))
-                {
-                    if (iter.depth > maxDepth)
-                        maxDepth = iter.depth;
+                    thread.maxDepth = iter.maxDepth;
                 }
+                thread.alive = true;
             }
-            return maxDepth;
+            m_LastSelectedFrameID = frameIndex;
         }
 
         private float CalculateHeightForAllBars(Rect fullRect, out float combinedHeaderHeight, out float combinedThreadHeight)
@@ -1190,200 +1172,203 @@ void HandleThreadSplitterFoldoutButtons(GroupInfo group, ThreadInfo thread, Rect
 
         public void DoGUI(FrameDataView frameDataView, float width, float ypos, float height)
         {
-            if (frameDataView == null || !frameDataView.IsValid())
+            using (m_DoGUIMarker.Auto())
             {
-                GUILayout.Label(BaseStyles.noData, BaseStyles.label);
-                return;
-            }
-
-            Rect fullRect = new Rect(0, ypos - 1, width, height + 1);
-            float sideWidth = Chart.kSideWidth - 1;
+                if (frameDataView == null || !frameDataView.IsValid())
+                {
+                    GUILayout.Label(BaseStyles.noData, BaseStyles.label);
+                    return;
+                }
 
-            Rect timeRulerRect = new Rect(fullRect.x + sideWidth, fullRect.y, fullRect.width - sideWidth, k_LineHeight);
+                Rect fullRect = new Rect(0, ypos - 1, width, height + 1);
+                float sideWidth = Chart.kSideWidth - 1;
 
-            Rect timeAreaRect = new Rect(fullRect.x + sideWidth, fullRect.y + timeRulerRect.height, fullRect.width - sideWidth, fullRect.height - timeRulerRect.height);
+                Rect timeRulerRect = new Rect(fullRect.x + sideWidth, fullRect.y, fullRect.width - sideWidth, k_LineHeight);
 
-            bool initializing = false;
-            if (m_TimeArea == null)
-            {
-                initializing = true;
-                m_TimeArea = new ZoomableArea();
-                m_TimeArea.hRangeLocked = false;
-                m_TimeArea.vRangeLocked = false;
-                m_TimeArea.hSlider = true;
-                m_TimeArea.vSlider = true;
-                m_TimeArea.vAllowExceedBaseRangeMax = false;
-                m_TimeArea.vAllowExceedBaseRangeMin = false;
-                m_TimeArea.hBaseRangeMin = 0;
-                m_TimeArea.vBaseRangeMin = 0;
-                m_TimeArea.vScaleMax = 1f;
-                m_TimeArea.vScaleMin = 1f;
-                m_TimeArea.scaleWithWindow = true;
-                m_TimeArea.margin = 10;
-                m_TimeArea.topmargin = 0;
-                m_TimeArea.bottommargin = 0;
-                m_TimeArea.upDirection = ZoomableArea.YDirection.Negative;
-                m_TimeArea.vZoomLockedByDefault = true;
-            }
+                Rect timeAreaRect = new Rect(fullRect.x + sideWidth, fullRect.y + timeRulerRect.height, fullRect.width - sideWidth, fullRect.height - timeRulerRect.height);
 
-            m_TimeArea.rect = timeAreaRect;
+                bool initializing = false;
+                if (m_TimeArea == null)
+                {
+                    initializing = true;
+                    m_TimeArea = new ZoomableArea();
+                    m_TimeArea.hRangeLocked = false;
+                    m_TimeArea.vRangeLocked = false;
+                    m_TimeArea.hSlider = true;
+                    m_TimeArea.vSlider = true;
+                    m_TimeArea.vAllowExceedBaseRangeMax = false;
+                    m_TimeArea.vAllowExceedBaseRangeMin = false;
+                    m_TimeArea.hBaseRangeMin = 0;
+                    m_TimeArea.vBaseRangeMin = 0;
+                    m_TimeArea.vScaleMax = 1f;
+                    m_TimeArea.vScaleMin = 1f;
+                    m_TimeArea.scaleWithWindow = true;
+                    m_TimeArea.margin = 10;
+                    m_TimeArea.topmargin = 0;
+                    m_TimeArea.bottommargin = 0;
+                    m_TimeArea.upDirection = ZoomableArea.YDirection.Negative;
+                    m_TimeArea.vZoomLockedByDefault = true;
+                }
 
-            Rect bottomLeftFillRect = new Rect(0, ypos + height - m_TimeArea.vSliderWidth, sideWidth, m_TimeArea.vSliderWidth);
+                m_TimeArea.rect = timeAreaRect;
 
-            if (Event.current.type == EventType.Repaint)
-            {
-                styles.profilerGraphBackground.Draw(fullRect, false, false, false, false);
-                // The bar in the lower left side that fills the space next to the horizontal scrollbar.
-                EditorStyles.toolbar.Draw(bottomLeftFillRect, false, false, false, false);
-            }
+                Rect bottomLeftFillRect = new Rect(0, ypos + height - m_TimeArea.vSliderWidth, sideWidth, m_TimeArea.vSliderWidth);
 
-            if (initializing)
-            {
-                NativeProfilerTimeline_InitializeArgs args = new NativeProfilerTimeline_InitializeArgs();
-                args.Reset();
-                args.ghostAlpha = 0.3f;
-                args.nonSelectedAlpha = 0.75f;
-                args.guiStyle = styles.bar.m_Ptr;
-                args.lineHeight = k_LineHeight;
-                args.textFadeOutWidth = k_TextFadeOutWidth;
-                args.textFadeStartWidth = k_TextFadeStartWidth;
-
-                NativeProfilerTimeline.Initialize(ref args);
-            }
-            // Prepare group and Thread Info
-            var iter = new ProfilerFrameDataIterator();
-            int threadCount = iter.GetThreadCount(frameDataView.frameIndex);
-            iter.SetRoot(frameDataView.frameIndex, 0);
-            UpdateGroupAndThreadInfo(ref iter, frameDataView.frameIndex);
-            MarkDeadOrClearThread();
+                if (Event.current.type == EventType.Repaint)
+                {
+                    styles.profilerGraphBackground.Draw(fullRect, false, false, false, false);
+                    // The bar in the lower left side that fills the space next to the horizontal scrollbar.
+                    EditorStyles.toolbar.Draw(bottomLeftFillRect, false, false, false, false);
+                }
 
-            HandleFrameSelected(iter.frameTimeMS);
+                if (initializing)
+                {
+                    NativeProfilerTimeline_InitializeArgs args = new NativeProfilerTimeline_InitializeArgs();
+                    args.Reset();
+                    args.ghostAlpha = 0.3f;
+                    args.nonSelectedAlpha = 0.75f;
+                    args.guiStyle = styles.bar.m_Ptr;
+                    args.lineHeight = k_LineHeight;
+                    args.textFadeOutWidth = k_TextFadeOutWidth;
+                    args.textFadeStartWidth = k_TextFadeStartWidth;
+
+                    NativeProfilerTimeline.Initialize(ref args);
+                }
+                // Prepare group and Thread Info
+                var iter = new ProfilerFrameDataIterator();
+                int threadCount = iter.GetThreadCount(frameDataView.frameIndex);
+                iter.SetRoot(frameDataView.frameIndex, 0);
+                UpdateGroupAndThreadInfo(ref iter, frameDataView.frameIndex);
+                MarkDeadOrClearThread();
 
-            // update time area to new bounds
-            float combinedHeaderHeight, combinedThreadHeight;
-            float heightForAllBars = CalculateHeightForAllBars(fullRect, out combinedHeaderHeight, out combinedThreadHeight);
-            float emptySpaceBelowBars = k_LineHeight * 3f;
+                HandleFrameSelected(iter.frameTimeMS);
 
-            // if needed, take up more empty space below, to fill up the ZoomableArea
-            emptySpaceBelowBars = Mathf.Max(emptySpaceBelowBars, timeAreaRect.height - heightForAllBars);
+                // update time area to new bounds
+                float combinedHeaderHeight, combinedThreadHeight;
+                float heightForAllBars = CalculateHeightForAllBars(fullRect, out combinedHeaderHeight, out combinedThreadHeight);
+                float emptySpaceBelowBars = k_LineHeight * 3f;
 
-            heightForAllBars += emptySpaceBelowBars;
+                // if needed, take up more empty space below, to fill up the ZoomableArea
+                emptySpaceBelowBars = Mathf.Max(emptySpaceBelowBars, timeAreaRect.height - heightForAllBars);
 
-            m_TimeArea.hBaseRangeMax = iter.frameTimeMS;
-            m_TimeArea.vBaseRangeMax = heightForAllBars;
+                heightForAllBars += emptySpaceBelowBars;
 
-            if (Mathf.Abs(heightForAllBars - m_LastHeightForAllBars) >= 0.5f || Mathf.Abs(fullRect.height - m_LastFullRectHeight) >= 0.5f)
-            {
-                m_LastHeightForAllBars = heightForAllBars;
-                m_LastFullRectHeight = fullRect.height;
+                m_TimeArea.hBaseRangeMax = iter.frameTimeMS;
+                m_TimeArea.vBaseRangeMax = heightForAllBars;
 
-                // set V range to enforce scale of 1 and to shift the shown area up in case the drawn area shrunk down
-                m_TimeArea.SetShownVRange(m_TimeArea.shownArea.y, m_TimeArea.shownArea.y + m_TimeArea.drawRect.height);
-            }
+                if (Mathf.Abs(heightForAllBars - m_LastHeightForAllBars) >= 0.5f || Mathf.Abs(fullRect.height - m_LastFullRectHeight) >= 0.5f)
+                {
+                    m_LastHeightForAllBars = heightForAllBars;
+                    m_LastFullRectHeight = fullRect.height;
 
-            // frame the selection if needed and before drawing the time area
-            if (initializing)
-                PerformFrameSelected(iter.frameTimeMS);
+                    // set V range to enforce scale of 1 and to shift the shown area up in case the drawn area shrunk down
+                    m_TimeArea.SetShownVRange(m_TimeArea.shownArea.y, m_TimeArea.shownArea.y + m_TimeArea.drawRect.height);
+                }
 
-            DoTimeRulerGUI(timeRulerRect, sideWidth, iter.frameTimeMS);
-            DoTimeArea();
+                // frame the selection if needed and before drawing the time area
+                if (initializing)
+                    PerformFrameSelected(iter.frameTimeMS);
 
-            Rect fullThreadsRect = new Rect(fullRect.x, fullRect.y + timeRulerRect.height, fullRect.width - m_TimeArea.vSliderWidth, fullRect.height - timeRulerRect.height - m_TimeArea.hSliderHeight);
+                DoTimeRulerGUI(timeRulerRect, sideWidth, iter.frameTimeMS);
+                DoTimeArea();
 
-            Rect fullThreadsRectWithoutSidebar = fullThreadsRect;
-            fullThreadsRectWithoutSidebar.x += sideWidth;
-            fullThreadsRectWithoutSidebar.width -= sideWidth;
+                Rect fullThreadsRect = new Rect(fullRect.x, fullRect.y + timeRulerRect.height, fullRect.width - m_TimeArea.vSliderWidth, fullRect.height - timeRulerRect.height - m_TimeArea.hSliderHeight);
 
-            // The splitters need to be handled after the time area so that they don't interfere with the input for panning/scrolling the ZoomableArea
-            DoThreadSplitters(fullThreadsRect, fullThreadsRectWithoutSidebar, frameDataView.frameIndex, ThreadSplitterCommand.HandleThreadSplitter);
+                Rect fullThreadsRectWithoutSidebar = fullThreadsRect;
+                fullThreadsRectWithoutSidebar.x += sideWidth;
+                fullThreadsRectWithoutSidebar.width -= sideWidth;
 
-            Rect barsUIRect = m_TimeArea.drawRect;
+                // The splitters need to be handled after the time area so that they don't interfere with the input for panning/scrolling the ZoomableArea
+                DoThreadSplitters(fullThreadsRect, fullThreadsRectWithoutSidebar, frameDataView.frameIndex, ThreadSplitterCommand.HandleThreadSplitter);
 
-            DrawGrid(barsUIRect, iter.frameTimeMS);
+                Rect barsUIRect = m_TimeArea.drawRect;
 
-            Rect barsAndSidebarUIRect = new Rect(barsUIRect.x - sideWidth, barsUIRect.y, barsUIRect.width + sideWidth, barsUIRect.height);
+                DrawGrid(barsUIRect, iter.frameTimeMS);
 
-            GUI.BeginClip(barsAndSidebarUIRect);
+                Rect barsAndSidebarUIRect = new Rect(barsUIRect.x - sideWidth, barsUIRect.y, barsUIRect.width + sideWidth, barsUIRect.height);
 
-            Rect shownBarsUIRect = barsUIRect;
-            shownBarsUIRect.y = scrollOffsetY;
+                GUI.BeginClip(barsAndSidebarUIRect);
 
-            // since the scale is not applied to the group headers, there would be some height unaccounted for
-            // this calculation applies that height to the threads via scaleForThreadHeight
-            float heightUnaccountedForDueToNotScalingHeaders = m_TimeArea.scale.y * combinedHeaderHeight - combinedHeaderHeight;
-            float scaleForThreadHeight = (combinedThreadHeight * m_TimeArea.scale.y + heightUnaccountedForDueToNotScalingHeaders) / combinedThreadHeight;
+                Rect shownBarsUIRect = barsUIRect;
+                shownBarsUIRect.y = scrollOffsetY;
 
-            DrawBars(shownBarsUIRect, scaleForThreadHeight);
-            GUI.EndClip();
+                // since the scale is not applied to the group headers, there would be some height unaccounted for
+                // this calculation applies that height to the threads via scaleForThreadHeight
+                float heightUnaccountedForDueToNotScalingHeaders = m_TimeArea.scale.y * combinedHeaderHeight - combinedHeaderHeight;
+                float scaleForThreadHeight = (combinedThreadHeight * m_TimeArea.scale.y + heightUnaccountedForDueToNotScalingHeaders) / combinedThreadHeight;
 
-            DoRangeSelection(barsUIRect);
+                DrawBars(shownBarsUIRect, scaleForThreadHeight);
+                GUI.EndClip();
 
-            GUI.BeginClip(barsUIRect);
-            shownBarsUIRect.x = 0;
+                DoRangeSelection(barsUIRect);
 
-            bool oldEnabled = GUI.enabled;
-            GUI.enabled = false;
-            // Walk backwards to find how many previous frames we need to show.
-            int maxContextFramesToShow = m_Window.IsRecording() ? 1 : 3;
-            int numContextFramesToShow = maxContextFramesToShow;
-            int currentFrame = frameDataView.frameIndex;
-            float currentTime = 0;
-            do
-            {
-                int prevFrame = ProfilerDriver.GetPreviousFrameIndex(currentFrame);
-                if (prevFrame == -1)
-                    break;
-                iter.SetRoot(prevFrame, 0);
-                currentTime -= iter.frameTimeMS;
-                currentFrame = prevFrame;
-                --numContextFramesToShow;
-            }
-            while (currentTime > m_TimeArea.shownArea.x && numContextFramesToShow > 0);
+                GUI.BeginClip(barsUIRect);
+                shownBarsUIRect.x = 0;
 
-            // Draw previous frames
-            while (currentFrame != -1 && currentFrame != frameDataView.frameIndex)
-            {
-                iter.SetRoot(currentFrame, 0);
-                DoProfilerFrame(currentFrame, shownBarsUIRect, true, threadCount, currentTime, scaleForThreadHeight);
-                currentTime += iter.frameTimeMS;
-                currentFrame = ProfilerDriver.GetNextFrameIndex(currentFrame);
-            }
+                bool oldEnabled = GUI.enabled;
+                GUI.enabled = false;
+                // Walk backwards to find how many previous frames we need to show.
+                int maxContextFramesToShow = m_Window.IsRecording() ? 1 : 3;
+                int numContextFramesToShow = maxContextFramesToShow;
+                int currentFrame = frameDataView.frameIndex;
+                float currentTime = 0;
+                do
+                {
+                    int prevFrame = ProfilerDriver.GetPreviousFrameIndex(currentFrame);
+                    if (prevFrame == -1)
+                        break;
+                    iter.SetRoot(prevFrame, 0);
+                    currentTime -= iter.frameTimeMS;
+                    currentFrame = prevFrame;
+                    --numContextFramesToShow;
+                }
+                while (currentTime > m_TimeArea.shownArea.x && numContextFramesToShow > 0);
 
-            // Draw next frames
-            numContextFramesToShow = maxContextFramesToShow;
-            currentFrame = frameDataView.frameIndex;
-            currentTime = 0;
-            while (currentTime < m_TimeArea.shownArea.x + m_TimeArea.shownArea.width && numContextFramesToShow >= 0)
-            {
-                if (frameDataView.frameIndex != currentFrame)
+                // Draw previous frames
+                while (currentFrame != -1 && currentFrame != frameDataView.frameIndex)
+                {
+                    iter.SetRoot(currentFrame, 0);
                     DoProfilerFrame(currentFrame, shownBarsUIRect, true, threadCount, currentTime, scaleForThreadHeight);
-                iter.SetRoot(currentFrame, 0);
-                currentFrame = ProfilerDriver.GetNextFrameIndex(currentFrame);
-                if (currentFrame == -1)
-                    break;
-                currentTime += iter.frameTimeMS;
-                --numContextFramesToShow;
-            }
+                    currentTime += iter.frameTimeMS;
+                    currentFrame = ProfilerDriver.GetNextFrameIndex(currentFrame);
+                }
+
+                // Draw next frames
+                numContextFramesToShow = maxContextFramesToShow;
+                currentFrame = frameDataView.frameIndex;
+                currentTime = 0;
+                while (currentTime < m_TimeArea.shownArea.x + m_TimeArea.shownArea.width && numContextFramesToShow >= 0)
+                {
+                    if (frameDataView.frameIndex != currentFrame)
+                        DoProfilerFrame(currentFrame, shownBarsUIRect, true, threadCount, currentTime, scaleForThreadHeight);
+                    iter.SetRoot(currentFrame, 0);
+                    currentFrame = ProfilerDriver.GetNextFrameIndex(currentFrame);
+                    if (currentFrame == -1)
+                        break;
+                    currentTime += iter.frameTimeMS;
+                    --numContextFramesToShow;
+                }
 
-            GUI.enabled = oldEnabled;
+                GUI.enabled = oldEnabled;
 
-            // Draw center frame last to get on top
-            threadCount = 0;
-            DoProfilerFrame(frameDataView.frameIndex, shownBarsUIRect, false, threadCount, 0, scaleForThreadHeight);
+                // Draw center frame last to get on top
+                threadCount = 0;
+                DoProfilerFrame(frameDataView.frameIndex, shownBarsUIRect, false, threadCount, 0, scaleForThreadHeight);
 
-            GUI.EndClip();
+                GUI.EndClip();
 
-            // Draw Foldout Buttons on top of natively drawn bars
-            DoThreadSplitters(fullThreadsRect, fullThreadsRectWithoutSidebar, frameDataView.frameIndex, ThreadSplitterCommand.HandleThreadSplitterFoldoutButtons);
+                // Draw Foldout Buttons on top of natively drawn bars
+                DoThreadSplitters(fullThreadsRect, fullThreadsRectWithoutSidebar, frameDataView.frameIndex, ThreadSplitterCommand.HandleThreadSplitterFoldoutButtons);
 
-            // Draw tooltips on top of clip to be able to extend outside of timeline area
-            DoSelectionTooltip(frameDataView.frameIndex, m_TimeArea.drawRect);
+                // Draw tooltips on top of clip to be able to extend outside of timeline area
+                DoSelectionTooltip(frameDataView.frameIndex, m_TimeArea.drawRect);
 
-            if (Event.current.type == EventType.Repaint)
-            {
-                // Reset all flags once Repaint finished on this view
-                m_LastRepaintProcessedInputs = m_CurrentlyProcessedInputs;
-                m_CurrentlyProcessedInputs = 0;
+                if (Event.current.type == EventType.Repaint)
+                {
+                    // Reset all flags once Repaint finished on this view
+                    m_LastRepaintProcessedInputs = m_CurrentlyProcessedInputs;
+                    m_CurrentlyProcessedInputs = 0;
+                }
             }
         }
 
diff --git a/Modules/ProfilerEditor/ProfilerWindow/ProfilerWindow.cs b/Modules/ProfilerEditor/ProfilerWindow/ProfilerWindow.cs
index 1228f2fe70..127ff30dbb 100644
--- a/Modules/ProfilerEditor/ProfilerWindow/ProfilerWindow.cs
+++ b/Modules/ProfilerEditor/ProfilerWindow/ProfilerWindow.cs
@@ -107,7 +107,8 @@ static Styles()
         private Vector2 m_GraphPos = Vector2.zero;
         private Vector2[] m_PaneScroll = new Vector2[Profiler.areaCount];
         private Vector2 m_PaneScroll_AudioChannels = Vector2.zero;
-        private Vector2 m_PaneScroll_AudioDSP = Vector2.zero;
+        private Vector2 m_PaneScroll_AudioDSPLeft = Vector2.zero;
+        private Vector2 m_PaneScroll_AudioDSPRight = Vector2.zero;
         private Vector2 m_PaneScroll_AudioClips = Vector2.zero;
 
         [SerializeField]
@@ -122,7 +123,7 @@ static Styles()
         ProfilerArea? m_CurrentArea = ProfilerArea.CPU;
 
         ProfilerMemoryView m_ShowDetailedMemoryPane = ProfilerMemoryView.Simple;
-        ProfilerAudioView m_ShowDetailedAudioPane = ProfilerAudioView.Stats;
+        ProfilerAudioView m_ShowDetailedAudioPane = ProfilerAudioView.Channels;
 
         [SerializeField]
         bool m_ShowInactiveDSPChains = false;
@@ -837,194 +838,192 @@ void DrawNetworkOperationsPane()
         }
 
 
-        private void AudioProfilerToggle(ProfilerCaptureFlags toggleFlag)
+        private enum ProfilerAudioPopupItems
         {
-            bool oldState = (AudioSettings.profilerCaptureFlags & (int)toggleFlag) != 0;
-            bool newState = GUILayout.Toggle(oldState, "Record", EditorStyles.toolbarButton);
-            if (oldState != newState)
-                ProfilerDriver.SetAudioCaptureFlags((AudioSettings.profilerCaptureFlags & ~(int)toggleFlag) | (newState
-                    ? (int)toggleFlag
-                    : 0));
+            Simple = 0,
+            Detailed = 1
+        }
+
+        private bool AudioDeepProfileToggle()
+        {
+            int toggleFlags = (int)ProfilerCaptureFlags.Channels;
+            if (Unsupported.IsDeveloperMode())
+                toggleFlags |= (int)ProfilerCaptureFlags.Clips | (int)ProfilerCaptureFlags.DSPNodes;
+            ProfilerAudioPopupItems oldShowDetailedAudioPane = (AudioSettings.profilerCaptureFlags & toggleFlags) != 0 ? ProfilerAudioPopupItems.Detailed : ProfilerAudioPopupItems.Simple;
+            ProfilerAudioPopupItems newShowDetailedAudioPane = (ProfilerAudioPopupItems)EditorGUILayout.EnumPopup(oldShowDetailedAudioPane, EditorStyles.toolbarDropDown, GUILayout.Width(70f));
+            if (oldShowDetailedAudioPane != newShowDetailedAudioPane)
+                ProfilerDriver.SetAudioCaptureFlags((AudioSettings.profilerCaptureFlags & ~toggleFlags) | (newShowDetailedAudioPane == ProfilerAudioPopupItems.Detailed ? toggleFlags : 0));
+            return (AudioSettings.profilerCaptureFlags & toggleFlags) != 0;
+        }
+
+        private Rect DrawAudioStatsPane(ref Vector2 scrollPos)
+        {
+            var totalRect = GUILayoutUtility.GetRect(20f, 20000f, 10, 10000f);
+            var statsRect = new Rect(totalRect.x, totalRect.y, 230f, totalRect.height);
+            var rightRect = new Rect(statsRect.xMax, totalRect.y, totalRect.width - statsRect.width, totalRect.height);
+
+            // STATS
+            var content = ProfilerDriver.GetOverviewText(m_CurrentArea.Value, GetActiveVisibleFrameIndex());
+            var textSize = EditorStyles.wordWrappedLabel.CalcSize(GUIContent.Temp(content));
+            scrollPos = GUI.BeginScrollView(statsRect, scrollPos, new Rect(0, 0, textSize.x, textSize.y));
+            GUI.Label(new Rect(3, 3, textSize.x, textSize.y), content, EditorStyles.wordWrappedLabel);
+            GUI.EndScrollView();
+            EditorGUI.DrawRect(new Rect(statsRect.xMax - 1, statsRect.y, 1, statsRect.height), Color.black);
+
+            return rightRect;
         }
 
         private void DrawAudioPane()
         {
             EditorGUILayout.BeginHorizontal(EditorStyles.toolbar);
             ProfilerAudioView newShowDetailedAudioPane = m_ShowDetailedAudioPane;
-            if (GUILayout.Toggle(newShowDetailedAudioPane == ProfilerAudioView.Stats, "Stats", EditorStyles.toolbarButton)) newShowDetailedAudioPane = ProfilerAudioView.Stats;
-            if (GUILayout.Toggle(newShowDetailedAudioPane == ProfilerAudioView.Channels, "Channels", EditorStyles.toolbarButton)) newShowDetailedAudioPane = ProfilerAudioView.Channels;
-            if (GUILayout.Toggle(newShowDetailedAudioPane == ProfilerAudioView.Groups, "Groups", EditorStyles.toolbarButton)) newShowDetailedAudioPane = ProfilerAudioView.Groups;
-            if (GUILayout.Toggle(newShowDetailedAudioPane == ProfilerAudioView.ChannelsAndGroups, "Channels and groups", EditorStyles.toolbarButton)) newShowDetailedAudioPane = ProfilerAudioView.ChannelsAndGroups;
-            if (Unsupported.IsDeveloperMode() && GUILayout.Toggle(newShowDetailedAudioPane == ProfilerAudioView.DSPGraph, "DSP Graph", EditorStyles.toolbarButton)) newShowDetailedAudioPane = ProfilerAudioView.DSPGraph;
-            if (Unsupported.IsDeveloperMode() && GUILayout.Toggle(newShowDetailedAudioPane == ProfilerAudioView.Clips, "Clips", EditorStyles.toolbarButton)) newShowDetailedAudioPane = ProfilerAudioView.Clips;
-            if (newShowDetailedAudioPane != m_ShowDetailedAudioPane)
-            {
-                m_ShowDetailedAudioPane = newShowDetailedAudioPane;
-                m_LastAudioProfilerFrame = -1; // force update
-            }
-            if (m_ShowDetailedAudioPane == ProfilerAudioView.Stats)
-            {
-                GUILayout.Space(5);
-                GUILayout.FlexibleSpace();
-                EditorGUILayout.EndHorizontal();
-                DrawOverviewText(m_CurrentArea);
-            }
-            else if (m_ShowDetailedAudioPane == ProfilerAudioView.DSPGraph)
+            if (AudioDeepProfileToggle())
             {
-                GUILayout.Space(5);
-                AudioProfilerToggle(ProfilerCaptureFlags.DSPNodes);
-                GUILayout.Space(5);
-                m_ShowInactiveDSPChains = GUILayout.Toggle(m_ShowInactiveDSPChains, "Show inactive", EditorStyles.toolbarButton);
-                if (m_ShowInactiveDSPChains)
-                    m_HighlightAudibleDSPChains = GUILayout.Toggle(m_HighlightAudibleDSPChains, "Highlight audible", EditorStyles.toolbarButton);
-                GUILayout.FlexibleSpace();
-                EditorGUILayout.EndHorizontal();
+                if (GUILayout.Toggle(newShowDetailedAudioPane == ProfilerAudioView.Channels, "Channels", EditorStyles.toolbarButton)) newShowDetailedAudioPane = ProfilerAudioView.Channels;
+                if (GUILayout.Toggle(newShowDetailedAudioPane == ProfilerAudioView.Groups, "Groups", EditorStyles.toolbarButton)) newShowDetailedAudioPane = ProfilerAudioView.Groups;
+                if (GUILayout.Toggle(newShowDetailedAudioPane == ProfilerAudioView.ChannelsAndGroups, "Channels and groups", EditorStyles.toolbarButton)) newShowDetailedAudioPane = ProfilerAudioView.ChannelsAndGroups;
+                if (Unsupported.IsDeveloperMode() && GUILayout.Toggle(newShowDetailedAudioPane == ProfilerAudioView.DSPGraph, "DSP Graph", EditorStyles.toolbarButton)) newShowDetailedAudioPane = ProfilerAudioView.DSPGraph;
+                if (Unsupported.IsDeveloperMode() && GUILayout.Toggle(newShowDetailedAudioPane == ProfilerAudioView.Clips, "Clips", EditorStyles.toolbarButton)) newShowDetailedAudioPane = ProfilerAudioView.Clips;
+                if (newShowDetailedAudioPane != m_ShowDetailedAudioPane)
+                {
+                    m_ShowDetailedAudioPane = newShowDetailedAudioPane;
+                    m_LastAudioProfilerFrame = -1; // force update
+                }
+                if (m_ShowDetailedAudioPane == ProfilerAudioView.DSPGraph)
+                {
+                    m_ShowInactiveDSPChains = GUILayout.Toggle(m_ShowInactiveDSPChains, "Show inactive", EditorStyles.toolbarButton);
+                    if (m_ShowInactiveDSPChains)
+                        m_HighlightAudibleDSPChains = GUILayout.Toggle(m_HighlightAudibleDSPChains, "Highlight audible", EditorStyles.toolbarButton);
+                    GUILayout.FlexibleSpace();
+                    EditorGUILayout.EndHorizontal();
 
-                var totalRect = GUILayoutUtility.GetRect(20f, 10000f, 10, 20000f);
+                    var graphRect = DrawAudioStatsPane(ref m_PaneScroll_AudioDSPLeft);
 
-                m_PaneScroll_AudioDSP = GUI.BeginScrollView(totalRect, m_PaneScroll_AudioDSP, new Rect(0, 0, 10000, 20000));
+                    m_PaneScroll_AudioDSPRight = GUI.BeginScrollView(graphRect, m_PaneScroll_AudioDSPRight, new Rect(0, 0, 10000, 20000));
 
-                var clippingRect = new Rect(m_PaneScroll_AudioDSP.x, m_PaneScroll_AudioDSP.y, totalRect.width, totalRect.height);
+                    var clippingRect = new Rect(m_PaneScroll_AudioDSPRight.x, m_PaneScroll_AudioDSPRight.y, graphRect.width, graphRect.height);
 
-                if (m_AudioProfilerDSPView == null)
-                    m_AudioProfilerDSPView = new AudioProfilerDSPView();
+                    if (m_AudioProfilerDSPView == null)
+                        m_AudioProfilerDSPView = new AudioProfilerDSPView();
 
-                ProfilerProperty property = CreateProperty();
-                if (CheckFrameData(property))
-                {
-                    m_AudioProfilerDSPView.OnGUI(clippingRect, property, m_ShowInactiveDSPChains, m_HighlightAudibleDSPChains, ref m_DSPGraphZoomFactor, ref m_PaneScroll_AudioDSP);
-                }
-                if (property != null)
-                    property.Dispose();
+                    ProfilerProperty property = CreateProperty();
+                    if (CheckFrameData(property))
+                    {
+                        m_AudioProfilerDSPView.OnGUI(clippingRect, property, m_ShowInactiveDSPChains, m_HighlightAudibleDSPChains, ref m_DSPGraphZoomFactor, ref m_PaneScroll_AudioDSPRight);
+                    }
+                    if (property != null)
+                        property.Dispose();
 
-                GUI.EndScrollView();
+                    GUI.EndScrollView();
 
-                Repaint();
-            }
-            else if (m_ShowDetailedAudioPane == ProfilerAudioView.Clips)
-            {
-                GUILayout.Space(5);
-                AudioProfilerToggle(ProfilerCaptureFlags.Clips);
-                GUILayout.FlexibleSpace();
-                EditorGUILayout.EndHorizontal();
-
-                var totalRect = GUILayoutUtility.GetRect(20f, 20000f, 10, 10000f);
-                var statsRect = new Rect(totalRect.x, totalRect.y, 230f, totalRect.height);
-                var treeRect = new Rect(statsRect.xMax, totalRect.y, totalRect.width - statsRect.width, totalRect.height);
+                    Repaint();
+                }
+                else if (m_ShowDetailedAudioPane == ProfilerAudioView.Clips)
+                {
+                    GUILayout.FlexibleSpace();
+                    EditorGUILayout.EndHorizontal();
 
-                // STATS
-                var content = ProfilerDriver.GetOverviewText(m_CurrentArea.Value, GetActiveVisibleFrameIndex());
-                var textSize = EditorStyles.wordWrappedLabel.CalcSize(GUIContent.Temp(content));
-                m_PaneScroll_AudioClips = GUI.BeginScrollView(statsRect, m_PaneScroll_AudioClips, new Rect(0, 0, textSize.x, textSize.y));
-                GUI.Label(new Rect(3, 3, textSize.x, textSize.y), content, EditorStyles.wordWrappedLabel);
-                GUI.EndScrollView();
-                EditorGUI.DrawRect(new Rect(statsRect.xMax - 1, statsRect.y, 1, statsRect.height), Color.black);
+                    var treeRect = DrawAudioStatsPane(ref m_PaneScroll_AudioClips);
 
-                // TREE
-                if (m_AudioProfilerClipTreeViewState == null)
-                    m_AudioProfilerClipTreeViewState = new AudioProfilerClipTreeViewState();
+                    // TREE
+                    if (m_AudioProfilerClipTreeViewState == null)
+                        m_AudioProfilerClipTreeViewState = new AudioProfilerClipTreeViewState();
 
-                if (m_AudioProfilerClipViewBackend == null)
-                    m_AudioProfilerClipViewBackend = new AudioProfilerClipViewBackend(m_AudioProfilerClipTreeViewState);
+                    if (m_AudioProfilerClipViewBackend == null)
+                        m_AudioProfilerClipViewBackend = new AudioProfilerClipViewBackend(m_AudioProfilerClipTreeViewState);
 
-                ProfilerProperty property = CreateProperty();
-                if (CheckFrameData(property))
-                {
-                    if (m_CurrentFrame == -1 || m_LastAudioProfilerFrame != m_CurrentFrame)
+                    ProfilerProperty property = CreateProperty();
+                    if (CheckFrameData(property))
                     {
-                        m_LastAudioProfilerFrame = m_CurrentFrame;
-                        var sourceItems = property.GetAudioProfilerClipInfo();
-                        if (sourceItems != null && sourceItems.Length > 0)
+                        if (m_CurrentFrame == -1 || m_LastAudioProfilerFrame != m_CurrentFrame)
                         {
-                            var items = new List<AudioProfilerClipInfoWrapper>();
-                            foreach (var s in sourceItems)
-                            {
-                                items.Add(new AudioProfilerClipInfoWrapper(s, property.GetAudioProfilerNameByOffset(s.assetNameOffset)));
-                            }
-                            m_AudioProfilerClipViewBackend.SetData(items);
-                            if (m_AudioProfilerClipView == null)
+                            m_LastAudioProfilerFrame = m_CurrentFrame;
+                            var sourceItems = property.GetAudioProfilerClipInfo();
+                            if (sourceItems != null && sourceItems.Length > 0)
                             {
-                                m_AudioProfilerClipView = new AudioProfilerClipView(this, m_AudioProfilerClipTreeViewState);
-                                m_AudioProfilerClipView.Init(treeRect, m_AudioProfilerClipViewBackend);
+                                var items = new List<AudioProfilerClipInfoWrapper>();
+                                foreach (var s in sourceItems)
+                                {
+                                    items.Add(new AudioProfilerClipInfoWrapper(s, property.GetAudioProfilerNameByOffset(s.assetNameOffset)));
+                                }
+                                m_AudioProfilerClipViewBackend.SetData(items);
+                                if (m_AudioProfilerClipView == null)
+                                {
+                                    m_AudioProfilerClipView = new AudioProfilerClipView(this, m_AudioProfilerClipTreeViewState);
+                                    m_AudioProfilerClipView.Init(treeRect, m_AudioProfilerClipViewBackend);
+                                }
                             }
                         }
+                        if (m_AudioProfilerClipView != null)
+                            m_AudioProfilerClipView.OnGUI(treeRect);
                     }
-                    if (m_AudioProfilerClipView != null)
-                        m_AudioProfilerClipView.OnGUI(treeRect);
+                    if (property != null)
+                        property.Dispose();
                 }
-                if (property != null)
-                    property.Dispose();
-            }
-            else
-            {
-                GUILayout.Space(5);
-                AudioProfilerToggle(ProfilerCaptureFlags.Channels);
-                GUILayout.Space(5);
-                bool resetAllAudioClipPlayCountsOnPlay = GUILayout.Toggle(AudioUtil.resetAllAudioClipPlayCountsOnPlay, "Reset play count on play", EditorStyles.toolbarButton);
-                if (resetAllAudioClipPlayCountsOnPlay != AudioUtil.resetAllAudioClipPlayCountsOnPlay)
-                    AudioUtil.resetAllAudioClipPlayCountsOnPlay = resetAllAudioClipPlayCountsOnPlay;
-                if (Unsupported.IsDeveloperMode())
+                else
                 {
-                    GUILayout.Space(5);
-                    bool showAllGroups = EditorPrefs.GetBool("AudioProfilerShowAllGroups");
-                    bool newShowAllGroups = GUILayout.Toggle(showAllGroups, "Show all groups (dev mode only)", EditorStyles.toolbarButton);
-                    if (showAllGroups != newShowAllGroups)
-                        EditorPrefs.SetBool("AudioProfilerShowAllGroups", newShowAllGroups);
-                }
-                GUILayout.FlexibleSpace();
-                EditorGUILayout.EndHorizontal();
-
-                var totalRect = GUILayoutUtility.GetRect(20f, 20000f, 10, 10000f);
-                var statsRect = new Rect(totalRect.x, totalRect.y, 230f, totalRect.height);
-                var treeRect = new Rect(statsRect.xMax, totalRect.y, totalRect.width - statsRect.width, totalRect.height);
+                    bool resetAllAudioClipPlayCountsOnPlay = GUILayout.Toggle(AudioUtil.resetAllAudioClipPlayCountsOnPlay, "Reset play count on play", EditorStyles.toolbarButton);
+                    if (resetAllAudioClipPlayCountsOnPlay != AudioUtil.resetAllAudioClipPlayCountsOnPlay)
+                        AudioUtil.resetAllAudioClipPlayCountsOnPlay = resetAllAudioClipPlayCountsOnPlay;
+                    if (Unsupported.IsDeveloperMode())
+                    {
+                        GUILayout.Space(5);
+                        bool showAllGroups = EditorPrefs.GetBool("AudioProfilerShowAllGroups");
+                        bool newShowAllGroups = GUILayout.Toggle(showAllGroups, "Show all groups (dev mode only)", EditorStyles.toolbarButton);
+                        if (showAllGroups != newShowAllGroups)
+                            EditorPrefs.SetBool("AudioProfilerShowAllGroups", newShowAllGroups);
+                    }
+                    GUILayout.FlexibleSpace();
+                    EditorGUILayout.EndHorizontal();
 
-                // STATS
-                var content = ProfilerDriver.GetOverviewText(m_CurrentArea.Value, GetActiveVisibleFrameIndex());
-                var textSize = EditorStyles.wordWrappedLabel.CalcSize(GUIContent.Temp(content));
-                m_PaneScroll_AudioChannels = GUI.BeginScrollView(statsRect, m_PaneScroll_AudioChannels, new Rect(0, 0, textSize.x, textSize.y));
-                GUI.Label(new Rect(3, 3, textSize.x, textSize.y), content, EditorStyles.wordWrappedLabel);
-                GUI.EndScrollView();
-                EditorGUI.DrawRect(new Rect(statsRect.xMax - 1, statsRect.y, 1, statsRect.height), Color.black);
+                    var treeRect = DrawAudioStatsPane(ref m_PaneScroll_AudioChannels);
 
-                // TREE
-                if (m_AudioProfilerGroupTreeViewState == null)
-                    m_AudioProfilerGroupTreeViewState = new AudioProfilerGroupTreeViewState();
+                    // TREE
+                    if (m_AudioProfilerGroupTreeViewState == null)
+                        m_AudioProfilerGroupTreeViewState = new AudioProfilerGroupTreeViewState();
 
-                if (m_AudioProfilerGroupViewBackend == null)
-                    m_AudioProfilerGroupViewBackend = new AudioProfilerGroupViewBackend(m_AudioProfilerGroupTreeViewState);
+                    if (m_AudioProfilerGroupViewBackend == null)
+                        m_AudioProfilerGroupViewBackend = new AudioProfilerGroupViewBackend(m_AudioProfilerGroupTreeViewState);
 
-                ProfilerProperty property = CreateProperty();
-                if (CheckFrameData(property))
-                {
-                    if (m_CurrentFrame == -1 || m_LastAudioProfilerFrame != m_CurrentFrame)
+                    ProfilerProperty property = CreateProperty();
+                    if (CheckFrameData(property))
                     {
-                        m_LastAudioProfilerFrame = m_CurrentFrame;
-                        var sourceItems = property.GetAudioProfilerGroupInfo();
-                        if (sourceItems != null && sourceItems.Length > 0)
+                        if (m_CurrentFrame == -1 || m_LastAudioProfilerFrame != m_CurrentFrame)
                         {
-                            var items = new List<AudioProfilerGroupInfoWrapper>();
-                            foreach (var s in sourceItems)
-                            {
-                                bool isGroup = (s.flags & AudioProfilerGroupInfoHelper.AUDIOPROFILER_FLAGS_GROUP) != 0;
-                                if (m_ShowDetailedAudioPane == ProfilerAudioView.Channels && isGroup)
-                                    continue;
-                                if (m_ShowDetailedAudioPane == ProfilerAudioView.Groups && !isGroup)
-                                    continue;
-                                items.Add(new AudioProfilerGroupInfoWrapper(s, property.GetAudioProfilerNameByOffset(s.assetNameOffset), property.GetAudioProfilerNameByOffset(s.objectNameOffset), m_ShowDetailedAudioPane == ProfilerAudioView.Channels));
-                            }
-                            m_AudioProfilerGroupViewBackend.SetData(items);
-                            if (m_AudioProfilerGroupView == null)
+                            m_LastAudioProfilerFrame = m_CurrentFrame;
+                            var sourceItems = property.GetAudioProfilerGroupInfo();
+                            if (sourceItems != null && sourceItems.Length > 0)
                             {
-                                m_AudioProfilerGroupView = new AudioProfilerGroupView(this, m_AudioProfilerGroupTreeViewState);
-                                m_AudioProfilerGroupView.Init(treeRect, m_AudioProfilerGroupViewBackend);
+                                var items = new List<AudioProfilerGroupInfoWrapper>();
+                                foreach (var s in sourceItems)
+                                {
+                                    bool isGroup = (s.flags & AudioProfilerGroupInfoHelper.AUDIOPROFILER_FLAGS_GROUP) != 0;
+                                    if (m_ShowDetailedAudioPane == ProfilerAudioView.Channels && isGroup)
+                                        continue;
+                                    if (m_ShowDetailedAudioPane == ProfilerAudioView.Groups && !isGroup)
+                                        continue;
+                                    items.Add(new AudioProfilerGroupInfoWrapper(s, property.GetAudioProfilerNameByOffset(s.assetNameOffset), property.GetAudioProfilerNameByOffset(s.objectNameOffset), m_ShowDetailedAudioPane == ProfilerAudioView.Channels));
+                                }
+                                m_AudioProfilerGroupViewBackend.SetData(items);
+                                if (m_AudioProfilerGroupView == null)
+                                {
+                                    m_AudioProfilerGroupView = new AudioProfilerGroupView(this, m_AudioProfilerGroupTreeViewState);
+                                    m_AudioProfilerGroupView.Init(treeRect, m_AudioProfilerGroupViewBackend);
+                                }
                             }
                         }
+                        if (m_AudioProfilerGroupView != null)
+                            m_AudioProfilerGroupView.OnGUI(treeRect, m_ShowDetailedAudioPane == ProfilerAudioView.Channels);
                     }
-                    if (m_AudioProfilerGroupView != null)
-                        m_AudioProfilerGroupView.OnGUI(treeRect, m_ShowDetailedAudioPane == ProfilerAudioView.Channels);
+                    if (property != null)
+                        property.Dispose();
                 }
-                if (property != null)
-                    property.Dispose();
+            }
+            else
+            {
+                GUILayout.FlexibleSpace();
+                EditorGUILayout.EndHorizontal();
+                DrawOverviewText(m_CurrentArea);
             }
         }
 
diff --git a/Modules/ProfilerEditor/Public/ProfilerAPI.bindings.cs b/Modules/ProfilerEditor/Public/ProfilerAPI.bindings.cs
index b2b687f222..75bb8169db 100644
--- a/Modules/ProfilerEditor/Public/ProfilerAPI.bindings.cs
+++ b/Modules/ProfilerEditor/Public/ProfilerAPI.bindings.cs
@@ -54,7 +54,7 @@ public enum ProfilerMemoryView
 
     public enum ProfilerAudioView
     {
-        Stats = 0,
+        [Obsolete("This has been made obsolete. Audio stats are now shown on every subpane.", true)] Stats = 0,
         Channels = 1,
         Groups = 2,
         ChannelsAndGroups = 3,
diff --git a/Modules/ProfilerEditor/Public/ProfilerFrameDataIterator.bindings.cs b/Modules/ProfilerEditor/Public/ProfilerFrameDataIterator.bindings.cs
index 19037e8a21..c2ddb37866 100644
--- a/Modules/ProfilerEditor/Public/ProfilerFrameDataIterator.bindings.cs
+++ b/Modules/ProfilerEditor/Public/ProfilerFrameDataIterator.bindings.cs
@@ -63,6 +63,14 @@ public extern int depth
             get;
         }
 
+        /// <summary>
+        /// The maximal depth of the stacked samples. This count includes the thread root as well as counters.
+        /// </summary>
+        public extern int maxDepth
+        {
+            get;
+        }
+
         public extern string path
         {
             [NativeMethod("GetFunctionPath")]
diff --git a/Modules/ShortcutManagerEditor/ShortcutController.cs b/Modules/ShortcutManagerEditor/ShortcutController.cs
index 068fe5f33c..f551108c50 100644
--- a/Modules/ShortcutManagerEditor/ShortcutController.cs
+++ b/Modules/ShortcutManagerEditor/ShortcutController.cs
@@ -16,11 +16,17 @@ static ShortcutIntegration()
         {
             InitializeController();
             EditorApplication.globalEventHandler += EventHandler;
+            EditorApplication.doPressedKeysTriggerAnyShortcut += HasAnyEntriesHandler;
 
             // Need to reinitialize after project load if we want menu items
             EditorApplication.projectWasLoaded += InitializeController;
         }
 
+        static bool HasAnyEntriesHandler()
+        {
+            return instance.HasAnyEntries(Event.current);
+        }
+
         static void EventHandler()
         {
             instance.contextManager.SetFocusedWindow(EditorWindow.focusedWindow);
@@ -67,6 +73,11 @@ internal void Initialize(IShortcutProfileManager sender)
             m_Trigger = new Trigger(directory, new ConflictResolver());
         }
 
+        internal bool HasAnyEntries(Event evt)
+        {
+            return m_Trigger.HasAnyEntries();
+        }
+
         internal void HandleKeyEvent(Event evt)
         {
             m_Trigger.HandleKeyEvent(evt, contextManager);
diff --git a/Modules/ShortcutManagerEditor/Trigger.cs b/Modules/ShortcutManagerEditor/Trigger.cs
index 3aaf584b68..b388a2588a 100644
--- a/Modules/ShortcutManagerEditor/Trigger.cs
+++ b/Modules/ShortcutManagerEditor/Trigger.cs
@@ -130,6 +130,11 @@ public void HandleKeyEvent(Event evt, IContextManager contextManager)
             }
         }
 
+        public bool HasAnyEntries()
+        {
+            return m_Entries.Any();
+        }
+
         // filtered entries are expected to all be in the same context and/or null context and they all are known to share the prefix
         bool HasConflicts(List<ShortcutEntry> filteredEntries, List<KeyCombination> prefix)
         {
diff --git a/Modules/Tilemap/Managed/GridBrushBase.cs b/Modules/Tilemap/Managed/GridBrushBase.cs
index 73c38221d0..9b7bf651bb 100644
--- a/Modules/Tilemap/Managed/GridBrushBase.cs
+++ b/Modules/Tilemap/Managed/GridBrushBase.cs
@@ -49,5 +49,8 @@ public virtual void Pick(GridLayout gridLayout, GameObject brushTarget, BoundsIn
         public virtual void Move(GridLayout gridLayout, GameObject brushTarget, BoundsInt from, BoundsInt to) {}
         public virtual void MoveStart(GridLayout gridLayout, GameObject brushTarget, BoundsInt position) {}
         public virtual void MoveEnd(GridLayout gridLayout, GameObject brushTarget, BoundsInt position) {}
+
+        public virtual void ChangeZPosition(int change) {}
+        public virtual void ResetZPosition() {}
     }
 }
diff --git a/Modules/TilemapEditor/Editor/Managed/Grid/GridBrush.cs b/Modules/TilemapEditor/Editor/Managed/Grid/GridBrush.cs
index 9e14183cba..978133932c 100644
--- a/Modules/TilemapEditor/Editor/Managed/Grid/GridBrush.cs
+++ b/Modules/TilemapEditor/Editor/Managed/Grid/GridBrush.cs
@@ -453,6 +453,7 @@ public override int GetHashCode()
                 {
                     hash = tile != null ? tile.GetInstanceID() : 0;
                     hash = hash * 33 + matrix.GetHashCode();
+                    hash = hash * 33 + matrix.rotation.GetHashCode();
                     hash = hash * 33 + color.GetHashCode();
                 }
                 return hash;
diff --git a/Modules/TilemapEditor/Editor/Managed/Grid/GridBrushEditorBase.cs b/Modules/TilemapEditor/Editor/Managed/Grid/GridBrushEditorBase.cs
index 80d520831b..72ceacb7d1 100644
--- a/Modules/TilemapEditor/Editor/Managed/Grid/GridBrushEditorBase.cs
+++ b/Modules/TilemapEditor/Editor/Managed/Grid/GridBrushEditorBase.cs
@@ -56,6 +56,12 @@ internal static void OnPaintSceneGUIInternal(GridLayout gridLayout, GameObject b
             }
 
             GridEditorUtility.DrawGridMarquee(gridLayout, position, color);
+            if (position.zMin != 0)
+            {
+                var zeroBounds = position;
+                zeroBounds.zMin = 0;
+                GridEditorUtility.DrawGridMarquee(gridLayout, zeroBounds, Color.blue);
+            }
         }
     }
 }
diff --git a/Modules/TilemapEditor/Editor/Managed/Grid/GridPaintPaletteClipboard.cs b/Modules/TilemapEditor/Editor/Managed/Grid/GridPaintPaletteClipboard.cs
index 74278db16c..fcdb778094 100644
--- a/Modules/TilemapEditor/Editor/Managed/Grid/GridPaintPaletteClipboard.cs
+++ b/Modules/TilemapEditor/Editor/Managed/Grid/GridPaintPaletteClipboard.cs
@@ -353,7 +353,7 @@ protected override void OnDisable()
 
         public override void OnGUI()
         {
-            if (guiRect.width == 0f || guiRect.height == 0f)
+            if (Mathf.Approximately(guiRect.width, 0f) || Mathf.Approximately(guiRect.height, 0f))
                 return;
 
             UpdateMouseGridPosition();
@@ -389,7 +389,7 @@ public override void OnGUI()
 
         public void OnViewSizeChanged(Rect oldSize, Rect newSize)
         {
-            if (oldSize.height * oldSize.width * newSize.height * newSize.width == 0f)
+            if (Mathf.Approximately(oldSize.height * oldSize.width * newSize.height * newSize.width, 0f))
                 return;
 
             Camera cam = previewUtility.camera;
@@ -625,13 +625,13 @@ private void RenderDragAndDropPreview()
             RectInt rect = TileDragAndDrop.GetMinMaxRect(m_HoverData.Keys.ToList());
             rect.position += mouseGridPosition;
             DragAndDrop.visualMode = DragAndDropVisualMode.Copy;
-            GridEditorUtility.DrawGridMarquee(grid, new BoundsInt(new Vector3Int(rect.xMin, rect.yMin, 0), new Vector3Int(rect.width, rect.height, 1)), Color.white);
+            GridEditorUtility.DrawGridMarquee(grid, new BoundsInt(new Vector3Int(rect.xMin, rect.yMin, zPosition), new Vector3Int(rect.width, rect.height, 1)), Color.white);
         }
 
         private void RenderGrid()
         {
             // MeshTopology.Lines doesn't give nice pixel perfect grid so we have to have separate codepath with MeshTopology.Quads specially for palette window here
-            if (m_GridMesh == null && grid.cellLayout == Grid.CellLayout.Rectangle)
+            if (m_GridMesh == null && grid.cellLayout == GridLayout.CellLayout.Rectangle)
                 m_GridMesh = GridEditorUtility.GenerateCachedGridMesh(grid, k_GridColor, 1f / LocalToScreenRatio(), paddedBoundsInt, MeshTopology.Quads);
 
             GridEditorUtility.DrawGridGizmo(grid, grid.transform, k_GridColor, ref m_GridMesh, ref m_GridMaterial);
@@ -750,7 +750,7 @@ public void SetEditorPreviewTile(Tilemap tilemap, Vector2Int position, TileBase
 
         public void SetTile(Tilemap tilemap, Vector2Int position, TileBase tile, Color color, Matrix4x4 matrix)
         {
-            Vector3Int pos3 = new Vector3Int(position.x, position.y, 0);
+            Vector3Int pos3 = new Vector3Int(position.x, position.y, zPosition);
             tilemap.SetTile(pos3, tile);
             tilemap.SetColor(pos3, color);
             tilemap.SetTransformMatrix(pos3, matrix);
@@ -809,7 +809,7 @@ protected override void PickBrush(BoundsInt position, Vector3Int pickingStart)
             gridBrush.Pick(grid, brushTarget, position, pickingStart);
 
             if (!PaintableGrid.InGridEditMode())
-                EditMode.ChangeEditMode(EditMode.SceneViewEditMode.GridPainting, new Bounds(), GridPaintingState.instance);
+                EditMode.ChangeEditMode(EditMode.SceneViewEditMode.GridPainting, GridPaintingState.instance);
 
             m_ActivePick = new RectInt(position.min.x, position.min.y, position.size.x, position.size.y);
         }
@@ -873,7 +873,7 @@ private void PingTileAsset(RectInt rect)
             // Only able to ping asset if only one asset is selected
             if (rect.size == Vector2Int.zero && tilemap != null)
             {
-                TileBase tile = tilemap.GetTile(new Vector3Int(rect.xMin, rect.yMin, 0));
+                TileBase tile = tilemap.GetTile(new Vector3Int(rect.xMin, rect.yMin, zPosition));
                 EditorGUIUtility.PingObject(tile);
                 Selection.activeObject = tile;
             }
@@ -931,29 +931,6 @@ protected void DrawSelectionGizmo(RectInt rect)
 
         private void HandleMouseEnterLeave()
         {
-            if (Event.current.type == EventType.MouseEnterWindow)
-            {
-                if (PaintableGrid.InGridEditMode())
-                {
-                    GridPaintingState.activeGrid = this;
-                    Event.current.Use();
-                }
-            }
-            else if (Event.current.type == EventType.MouseLeaveWindow)
-            {
-                if (m_PreviousMousePosition.HasValue && guiRect.Contains(m_PreviousMousePosition.Value) && GridPaintingState.activeBrushEditor != null)
-                {
-                    GridPaintingState.activeBrushEditor.OnMouseLeave();
-                }
-                m_PreviousMousePosition = null;
-                if (PaintableGrid.InGridEditMode())
-                {
-                    GridPaintingState.activeGrid = null;
-                    Event.current.Use();
-                    Repaint();
-                }
-            }
-
             if (guiRect.Contains(Event.current.mousePosition))
             {
                 if (m_PreviousMousePosition.HasValue && !guiRect.Contains(m_PreviousMousePosition.Value) || !m_PreviousMousePosition.HasValue)
@@ -998,7 +975,7 @@ private void CallOnPaintSceneGUI(Vector2Int position)
                 rect = new RectInt(GridSelection.position.xMin, GridSelection.position.yMin, GridSelection.position.size.x, GridSelection.position.size.y);
 
             var gridLayout = tilemap != null ? tilemap as GridLayout : grid as GridLayout;
-            BoundsInt brushBounds = new BoundsInt(new Vector3Int(rect.x, rect.y, 0), new Vector3Int(rect.width, rect.height, 1));
+            BoundsInt brushBounds = new BoundsInt(new Vector3Int(rect.x, rect.y, zPosition), new Vector3Int(rect.width, rect.height, 1));
 
             if (GridPaintingState.activeBrushEditor != null)
                 GridPaintingState.activeBrushEditor.OnPaintSceneGUI(gridLayout, brushTarget, brushBounds, EditModeToBrushTool(EditMode.editMode), m_MarqueeStart.HasValue || executing);
diff --git a/Modules/TilemapEditor/Editor/Managed/Grid/GridPaintPaletteWindow.cs b/Modules/TilemapEditor/Editor/Managed/Grid/GridPaintPaletteWindow.cs
index 04dc841fa8..4cf48e9b5b 100644
--- a/Modules/TilemapEditor/Editor/Managed/Grid/GridPaintPaletteWindow.cs
+++ b/Modules/TilemapEditor/Editor/Managed/Grid/GridPaintPaletteWindow.cs
@@ -97,6 +97,8 @@ static class Styles
             public static readonly GUIContent tilePalette = EditorGUIUtility.TrTextContent("Tile Palette");
             public static readonly GUIContent edit = EditorGUIUtility.TrTextContent("Edit");
             public static readonly GUIContent editModified = EditorGUIUtility.TrTextContent("Edit*");
+            public static readonly GUIContent zPosition = EditorGUIUtility.TrTextContent("Z Position");
+            public static readonly GUIContent resetZPosition = EditorGUIUtility.TrTextContent("Reset");
             public static readonly GUIStyle ToolbarTitleStyle = "Toolbar";
             public static readonly GUIStyle dragHandle = "RL DragHandle";
             public static readonly float dragPadding = 3f;
@@ -280,6 +282,31 @@ static void FlipBrushY()
                 FlipBrush(GridBrush.FlipAxis.Y);
         }
 
+        static void ChangeBrushZ(int change)
+        {
+            GridPaintingState.gridBrush.ChangeZPosition(change);
+            GridPaintingState.activeGrid.ChangeZPosition(change);
+            GridPaintingState.activeGrid.Repaint();
+            foreach (var window in GridPaintPaletteWindow.instances)
+            {
+                window.Repaint();
+            }
+        }
+
+        [Shortcut("Grid Painting/Increase Z", typeof(ShortcutContext), "-")]
+        static void IncreaseBrushZ()
+        {
+            if (GridPaintingState.gridBrush != null && GridPaintingState.activeGrid != null)
+                ChangeBrushZ(1);
+        }
+
+        [Shortcut("Grid Painting/Decrease Z", typeof(ShortcutContext), "=")]
+        static void DecreaseBrushZ()
+        {
+            if (GridPaintingState.gridBrush != null && GridPaintingState.activeGrid != null)
+                ChangeBrushZ(-1);
+        }
+
         [SettingsProvider]
         internal static SettingsProvider CreateSettingsProvider()
         {
@@ -556,7 +583,9 @@ public void SavePalette()
                 GridPaintingState.savingPalette = true;
                 SetHideFlagsRecursivelyIgnoringTilemapChildren(paletteInstance, HideFlags.HideInHierarchy);
                 string path = AssetDatabase.GetAssetPath(palette);
+                #pragma warning disable CS0618 // Type or member is obsolete
                 PrefabUtility.ReplacePrefabAssetNameBased(paletteInstance, path, true);
+                #pragma warning restore CS0618 // Type or member is obsolete
                 SetHideFlagsRecursivelyIgnoringTilemapChildren(paletteInstance, HideFlags.HideAndDontSave);
                 GridPaintingState.savingPalette = false;
             }
@@ -688,6 +717,7 @@ public void OnEnable()
             GridPaintingState.brushChanged += OnBrushChanged;
             SceneView.onSceneGUIDelegate += OnSceneViewGUI;
             PrefabUtility.prefabInstanceUpdated += PrefabInstanceUpdated;
+            EditorApplication.projectWasLoaded += OnProjectLoaded;
 
             AssetPreview.SetPreviewTextureCacheSize(256, GetInstanceID());
             wantsMouseMove = true;
@@ -726,6 +756,12 @@ private void PrefabInstanceUpdated(GameObject updatedPrefab)
             }
         }
 
+        private void OnProjectLoaded()
+        {
+            // ShortcutIntegration instance is recreated after LoadLayout which wipes the OnEnable registration
+            ShortcutIntegration.instance.contextManager.RegisterToolContext(m_ShortcutContext);
+        }
+
         private void OnBrushChanged(GridBrushBase brush)
         {
             DisableFocus();
@@ -774,6 +810,7 @@ public void OnDisable()
             GridPaintingState.brushChanged -= OnBrushChanged;
             GridPaintingState.UnregisterPainterInterest(this);
             PrefabUtility.prefabInstanceUpdated -= PrefabInstanceUpdated;
+            EditorApplication.projectWasLoaded -= OnProjectLoaded;
 
             ShortcutIntegration.instance.contextManager.DeregisterToolContext(m_ShortcutContext);
         }
@@ -787,7 +824,7 @@ private void OnScenePaintTargetChanged(GameObject scenePaintTarget)
 
         public void ChangeToTool(GridBrushBase.Tool tool)
         {
-            EditMode.ChangeEditMode(PaintableGrid.BrushToolToEditMode(tool), new Bounds(Vector3.zero, Vector3.positiveInfinity), GridPaintingState.instance);
+            EditMode.ChangeEditMode(PaintableGrid.BrushToolToEditMode(tool), GridPaintingState.instance);
             Repaint();
         }
 
@@ -838,12 +875,18 @@ private void CallOnToolDeactivated()
             }
         }
 
+        internal void ResetZPosition()
+        {
+            GridPaintingState.gridBrush.ResetZPosition();
+            GridPaintingState.lastActiveGrid.ResetZPosition();
+        }
+
         private void OnBrushInspectorGUI()
         {
-            var brush = GridPaintingState.gridBrush;
-            if (brush == null)
+            if (GridPaintingState.gridBrush == null)
                 return;
 
+            // Brush Inspector GUI
             EditorGUI.BeginChangeCheck();
             if (GridPaintingState.activeBrushEditor != null)
                 GridPaintingState.activeBrushEditor.OnPaintInspectorGUI();
@@ -853,6 +896,25 @@ private void OnBrushInspectorGUI()
             {
                 GridPaletteBrushes.ActiveGridBrushAssetChanged();
             }
+
+            // Z Position Inspector
+            var hasLastActiveGrid = GridPaintingState.lastActiveGrid != null;
+            using (new EditorGUI.DisabledScope(!hasLastActiveGrid))
+            {
+                EditorGUILayout.BeginHorizontal();
+                EditorGUI.BeginChangeCheck();
+                var zPosition = EditorGUILayout.DelayedIntField(Styles.zPosition, hasLastActiveGrid ? GridPaintingState.lastActiveGrid.zPosition : 0);
+                if (EditorGUI.EndChangeCheck())
+                {
+                    GridPaintingState.gridBrush.ChangeZPosition(zPosition - GridPaintingState.lastActiveGrid.zPosition);
+                    GridPaintingState.lastActiveGrid.zPosition = zPosition;
+                }
+                if (GUILayout.Button(Styles.resetZPosition))
+                {
+                    ResetZPosition();
+                }
+                EditorGUILayout.EndHorizontal();
+            }
         }
 
         private bool IsObjectPrefabInstance(Object target)
@@ -938,19 +1000,19 @@ private void SelectTarget(int i, object o)
                         var option = EditorUtility.DisplayDialogComplex(TilePaletteProperties.targetEditModeDialogTitle
                             , TilePaletteProperties.targetEditModeDialogMessage
                             , TilePaletteProperties.targetEditModeDialogYes
-                            , TilePaletteProperties.targetEditModeDialogChange
-                            , TilePaletteProperties.targetEditModeDialogNo);
+                            , TilePaletteProperties.targetEditModeDialogNo
+                            , TilePaletteProperties.targetEditModeDialogChange);
                         switch (option)
                         {
                             case 0:
                                 GoToPrefabMode(obj);
                                 return;
                             case 1:
-                                var settingsWindow = SettingsWindow.Show(SettingsScopes.User);
-                                settingsWindow.FilterProviders(TilePaletteProperties.targetEditModeLookup);
+                                // Do nothing here for "No"
                                 break;
                             case 2:
-                                // Do nothing here for "No"
+                                var settingsWindow = SettingsWindow.Show(SettingsScopes.User);
+                                settingsWindow.FilterProviders(TilePaletteProperties.targetEditModeLookup);
                                 break;
                         }
                     }
@@ -1037,7 +1099,7 @@ private void OpenAddPalettePopup(Rect rect)
 
         private void OnClipboardGUI(Rect position)
         {
-            if (Event.current.type != EventType.Layout && position.Contains(Event.current.mousePosition) && GridPaintingState.activeGrid != clipboardView)
+            if (Event.current.type != EventType.Layout && position.Contains(Event.current.mousePosition) && GridPaintingState.activeGrid != clipboardView && clipboardView.unlocked)
             {
                 GridPaintingState.activeGrid = clipboardView;
                 SceneView.RepaintAll();
diff --git a/Modules/TilemapEditor/Editor/Managed/Grid/GridPaintingState.cs b/Modules/TilemapEditor/Editor/Managed/Grid/GridPaintingState.cs
index 7f25f4a305..9010374679 100644
--- a/Modules/TilemapEditor/Editor/Managed/Grid/GridPaintingState.cs
+++ b/Modules/TilemapEditor/Editor/Managed/Grid/GridPaintingState.cs
@@ -15,6 +15,7 @@ internal class GridPaintingState : ScriptableSingleton<GridPaintingState>, ITool
         [SerializeField] private GameObject m_ScenePaintTarget; // Which GameObject in scene is considered as painting target
         [SerializeField] private GridBrushBase m_Brush; // Which brush will handle painting callbacks
         [SerializeField] private PaintableGrid m_ActiveGrid; // Grid that has painting focus (can be palette, too)
+        [SerializeField] private PaintableGrid m_LastActiveGrid; // Grid that last had painting focus (can be palette, too)
         [SerializeField] private HashSet<Object> m_InterestedPainters = new HashSet<Object>(); // A list of objects that can paint using the GridPaintingState
 
         private GameObject[] m_CachedPaintTargets = null;
@@ -145,7 +146,17 @@ public static Editor fallbackEditor
         public static PaintableGrid activeGrid
         {
             get { return instance.m_ActiveGrid; }
-            set { instance.m_ActiveGrid = value; }
+            set
+            {
+                instance.m_ActiveGrid = value;
+                if (instance.m_ActiveGrid != null)
+                    instance.m_LastActiveGrid = value;
+            }
+        }
+
+        public static PaintableGrid lastActiveGrid
+        {
+            get { return instance.m_LastActiveGrid; }
         }
 
         public static bool ValidatePaintTarget(GameObject candidate)
diff --git a/Modules/TilemapEditor/Editor/Managed/Grid/PaintableGrid.cs b/Modules/TilemapEditor/Editor/Managed/Grid/PaintableGrid.cs
index b1dced7da9..4003031a24 100644
--- a/Modules/TilemapEditor/Editor/Managed/Grid/PaintableGrid.cs
+++ b/Modules/TilemapEditor/Editor/Managed/Grid/PaintableGrid.cs
@@ -53,11 +53,13 @@ protected virtual void OnBrushPickCancelled() {}
         private MarqueeType m_MarqueeType = MarqueeType.None;
         private bool m_IsExecuting;
         private EditMode.SceneViewEditMode m_ModeBeforePicking;
+        private int m_ZPosition;
 
         public Vector2Int mouseGridPosition { get { return m_MouseGridPosition; } }
         public bool isPicking { get { return m_MarqueeType == MarqueeType.Pick; } }
         public bool isBoxing { get { return m_MarqueeType == MarqueeType.Box; } }
         public Grid.CellLayout cellLayout { get { return CellLayout(); } }
+        public int zPosition { get { return m_ZPosition; } set { m_ZPosition = value; } }
 
         protected bool executing { get { return m_IsExecuting; } set { m_IsExecuting = value && isHotControl; } }
 
@@ -118,12 +120,17 @@ protected void UpdateMouseGridPosition()
                         newGridPosition.y = m_MouseGridPosition.y + Math.Sign(delta.y) * k_MaxMouseCellDelta;
                     m_PreviousMouseGridPosition = m_MouseGridPosition;
                     m_MouseGridPosition = newGridPosition;
-                    m_MouseGridPositionChanged = true;
-                    m_PositionChangeRepaintDone = false;
+                    MouseGridPositionChanged();
                 }
             }
         }
 
+        private void MouseGridPositionChanged()
+        {
+            m_MouseGridPositionChanged = true;
+            m_PositionChangeRepaintDone = false;
+        }
+
         private void HandleEditModeChange()
         {
             // Handles changes in EditMode while tool is expected to be in the same mode
@@ -178,7 +185,7 @@ private void HandleBrushPicking()
             if (evt.type == EventType.MouseDrag && isHotControl && m_MarqueeStart.HasValue && m_MarqueeType == MarqueeType.Pick && IsPickingEvent(evt))
             {
                 RectInt rect = GridEditorUtility.GetMarqueeRect(m_MarqueeStart.Value, mouseGridPosition);
-                OnBrushPickDragged(new BoundsInt(new Vector3Int(rect.xMin, rect.yMin, 0), new Vector3Int(rect.size.x, rect.size.y, 1)));
+                OnBrushPickDragged(new BoundsInt(new Vector3Int(rect.xMin, rect.yMin, zPosition), new Vector3Int(rect.size.x, rect.size.y, 1)));
                 Event.current.Use();
                 GUI.changed = true;
             }
@@ -189,7 +196,7 @@ private void HandleBrushPicking()
                 {
                     RectInt rect = GridEditorUtility.GetMarqueeRect(m_MarqueeStart.Value, mouseGridPosition);
                     Vector2Int pivot = GetMarqueePivot(m_MarqueeStart.Value, mouseGridPosition);
-                    PickBrush(new BoundsInt(new Vector3Int(rect.xMin, rect.yMin, 0), new Vector3Int(rect.size.x, rect.size.y, 1)), new Vector3Int(pivot.x, pivot.y, 0));
+                    PickBrush(new BoundsInt(new Vector3Int(rect.xMin, rect.yMin, zPosition), new Vector3Int(rect.size.x, rect.size.y, 1)), new Vector3Int(pivot.x, pivot.y, 0));
 
                     if (inEditMode && EditMode.editMode != m_ModeBeforePicking)
                     {
@@ -245,7 +252,7 @@ private void HandleSelectTool()
                 if (evt.type == EventType.MouseUp && m_MarqueeType == MarqueeType.Select)
                 {
                     RectInt rect = GridEditorUtility.GetMarqueeRect(m_MarqueeStart.Value, mouseGridPosition);
-                    Select(new BoundsInt(new Vector3Int(rect.xMin, rect.yMin, 0), new Vector3Int(rect.size.x, rect.size.y, 1)));
+                    Select(new BoundsInt(new Vector3Int(rect.xMin, rect.yMin, zPosition), new Vector3Int(rect.size.x, rect.size.y, 1)));
                     Event.current.Use();
                 }
                 if (evt.control)
@@ -288,7 +295,7 @@ private void HandleMoveTool()
                 {
                     executing = true;
                     BoundsInt previousRect = GridSelection.position;
-                    BoundsInt previousBounds = new BoundsInt(new Vector3Int(previousRect.xMin, previousRect.yMin, 0), new Vector3Int(previousRect.size.x, previousRect.size.y, 1));
+                    BoundsInt previousBounds = new BoundsInt(new Vector3Int(previousRect.xMin, previousRect.yMin, GridSelection.position.zMin), new Vector3Int(previousRect.size.x, previousRect.size.y, 1));
 
                     Vector2Int direction = mouseGridPosition - m_PreviousMove.Value;
                     BoundsInt pos = GridSelection.position;
@@ -326,13 +333,13 @@ private void HandleBrushPaintAndErase()
                     {
                         if (EditMode.editMode != EditMode.SceneViewEditMode.GridEraser)
                             EditMode.ChangeEditMode(EditMode.SceneViewEditMode.GridEraser, GridPaintingState.instance);
-                        Erase(new Vector3Int(mouseGridPosition.x, mouseGridPosition.y, 0));
+                        Erase(new Vector3Int(mouseGridPosition.x, mouseGridPosition.y, zPosition));
                     }
                     else
                     {
                         if (EditMode.editMode != EditMode.SceneViewEditMode.GridPainting)
                             EditMode.ChangeEditMode(EditMode.SceneViewEditMode.GridPainting, GridPaintingState.instance);
-                        Paint(new Vector3Int(mouseGridPosition.x, mouseGridPosition.y, 0));
+                        Paint(new Vector3Int(mouseGridPosition.x, mouseGridPosition.y, zPosition));
                     }
 
                     Event.current.Use();
@@ -350,9 +357,9 @@ private void HandleBrushPaintAndErase()
                         for (int i = 1; i < points.Count; i++)
                         {
                             if (IsErasingEvent(evt))
-                                Erase(new Vector3Int(points[i].x, points[i].y, 0));
+                                Erase(new Vector3Int(points[i].x, points[i].y, zPosition));
                             else
-                                Paint(new Vector3Int(points[i].x, points[i].y, 0));
+                                Paint(new Vector3Int(points[i].x, points[i].y, zPosition));
                         }
                         Event.current.Use();
                         GUI.changed = true;
@@ -405,7 +412,7 @@ private void HandleFloodFill()
                 {
                     executing = false;
                     RegisterUndo();
-                    FloodFill(new Vector3Int(mouseGridPosition.x, mouseGridPosition.y, 0));
+                    FloodFill(new Vector3Int(mouseGridPosition.x, mouseGridPosition.y, zPosition));
                     GUI.changed = true;
                     Event.current.Use();
                     GUIUtility.hotControl = 0;
@@ -442,9 +449,9 @@ private void HandleBoxTool()
                     RegisterUndo();
                     RectInt rect = GridEditorUtility.GetMarqueeRect(m_MarqueeStart.Value, mouseGridPosition);
                     if (evt.shift)
-                        BoxErase(new BoundsInt(rect.x, rect.y, 0, rect.size.x, rect.size.y, 1));
+                        BoxErase(new BoundsInt(rect.x, rect.y, zPosition, rect.size.x, rect.size.y, 1));
                     else
-                        BoxFill(new BoundsInt(rect.x, rect.y, 0, rect.size.x, rect.size.y, 1));
+                        BoxFill(new BoundsInt(rect.x, rect.y, zPosition, rect.size.x, rect.size.y, 1));
                     Event.current.Use();
                     executing = false;
                     GUI.changed = true;
@@ -464,6 +471,23 @@ private Vector2Int GetMarqueePivot(Vector2Int start, Vector2Int end)
             return pivot;
         }
 
+        public void ChangeZPosition(int change)
+        {
+            m_ZPosition += change;
+            MouseGridPositionChanged();
+            Repaint();
+        }
+
+        public void ResetZPosition()
+        {
+            if (m_ZPosition == 0)
+                return;
+
+            m_ZPosition = 0;
+            MouseGridPositionChanged();
+            Repaint();
+        }
+
         public static bool InGridEditMode()
         {
             return
diff --git a/Modules/TilemapEditor/Editor/Managed/Grid/PaintableSceneViewGrid.cs b/Modules/TilemapEditor/Editor/Managed/Grid/PaintableSceneViewGrid.cs
index f8f53f27df..4e5f28982b 100644
--- a/Modules/TilemapEditor/Editor/Managed/Grid/PaintableSceneViewGrid.cs
+++ b/Modules/TilemapEditor/Editor/Managed/Grid/PaintableSceneViewGrid.cs
@@ -320,16 +320,16 @@ void CallOnPaintSceneGUI()
                 rect = new RectInt(GridSelection.position.xMin, GridSelection.position.yMin, GridSelection.position.size.x, GridSelection.position.size.y);
 
             var layoutGrid = tilemap != null ? tilemap as GridLayout : grid as GridLayout;
-
+            BoundsInt brushBounds = new BoundsInt(new Vector3Int(rect.x, rect.y, zPosition), new Vector3Int(rect.width, rect.height, 1));
             if (GridPaintingState.activeBrushEditor != null)
             {
-                GridPaintingState.activeBrushEditor.OnPaintSceneGUI(layoutGrid, brushTarget,
-                    new BoundsInt(new Vector3Int(rect.x, rect.y, 0), new Vector3Int(rect.width, rect.height, 1)),
-                    EditModeToBrushTool(EditMode.editMode), m_MarqueeStart.HasValue || executing);
+                GridPaintingState.activeBrushEditor.OnPaintSceneGUI(layoutGrid, brushTarget, brushBounds
+                    , EditModeToBrushTool(EditMode.editMode), m_MarqueeStart.HasValue || executing);
             }
             else // Fallback when user hasn't defined custom editor
             {
-                GridBrushEditorBase.OnPaintSceneGUIInternal(layoutGrid, brushTarget, new BoundsInt(new Vector3Int(rect.x, rect.y, 0), new Vector3Int(rect.width, rect.height, 1)), EditModeToBrushTool(EditMode.editMode), m_MarqueeStart.HasValue || executing);
+                GridBrushEditorBase.OnPaintSceneGUIInternal(layoutGrid, brushTarget, brushBounds
+                    , EditModeToBrushTool(EditMode.editMode), m_MarqueeStart.HasValue || executing);
             }
         }
 
diff --git a/Modules/TilemapEditor/Editor/Managed/TilemapEditor.cs b/Modules/TilemapEditor/Editor/Managed/TilemapEditor.cs
index 36b436c627..292b2177bc 100644
--- a/Modules/TilemapEditor/Editor/Managed/TilemapEditor.cs
+++ b/Modules/TilemapEditor/Editor/Managed/TilemapEditor.cs
@@ -30,8 +30,10 @@ private static class Styles
             public static readonly GUIContent tilemapColorLabel = EditorGUIUtility.TrTextContent("Color", "Color tinting all Sprites from tiles in the tilemap");
             public static readonly GUIContent tileAnchorLabel = EditorGUIUtility.TrTextContent("Tile Anchor", "Anchoring position for Sprites from tiles in the tilemap");
             public static readonly GUIContent orientationLabel = EditorGUIUtility.TrTextContent("Orientation", "Orientation for tiles in the tilemap");
-            public static readonly GUIContent pointTopHexagonCreateUndo = EditorGUIUtility.TrTextContent("Hexagonal Point Top Tilemap");
-            public static readonly GUIContent flatTopHexagonCreateUndo = EditorGUIUtility.TrTextContent("Hexagonal Flat Top Tilemap");
+            public static readonly string pointTopHexagonCreateUndo = L10n.Tr("Hexagonal Point Top Tilemap");
+            public static readonly string flatTopHexagonCreateUndo = L10n.Tr("Hexagonal Flat Top Tilemap");
+            public static readonly string isometricCreateUndo = L10n.Tr("Isometric Tilemap");
+            public static readonly string isometricZAsYCreateUndo = L10n.Tr("Isometric Z As Y Tilemap");
         }
 
         private void OnEnable()
@@ -89,17 +91,28 @@ internal static void CreateRectangularTilemap()
         [MenuItem("GameObject/2D Object/Hexagonal Point Top Tilemap")]
         internal static void CreateHexagonalPointTopTilemap()
         {
-            CreateHexagonalTilemap(GridLayout.CellSwizzle.XYZ, Styles.pointTopHexagonCreateUndo.text);
+            CreateHexagonalTilemap(GridLayout.CellSwizzle.XYZ, Styles.pointTopHexagonCreateUndo);
         }
 
         [MenuItem("GameObject/2D Object/Hexagonal Flat Top Tilemap")]
         internal static void CreateHexagonalFlatTopTilemap()
         {
-            CreateHexagonalTilemap(GridLayout.CellSwizzle.YXZ, Styles.flatTopHexagonCreateUndo.text);
+            CreateHexagonalTilemap(GridLayout.CellSwizzle.YXZ, Styles.flatTopHexagonCreateUndo);
         }
 
         [MenuItem("GameObject/2D Object/Isometric Tilemap")]
         internal static void CreateIsometricTilemap()
+        {
+            CreateIsometricTilemap(GridLayout.CellLayout.Isometric, Styles.isometricCreateUndo);
+        }
+
+        [MenuItem("GameObject/2D Object/Isometric Z As Y Tilemap")]
+        internal static void CreateIsometricZAsYTilemap()
+        {
+            CreateIsometricTilemap(GridLayout.CellLayout.IsometricZAsY, Styles.isometricZAsYCreateUndo);
+        }
+
+        private static void CreateIsometricTilemap(GridLayout.CellLayout isometricLayout, string undoMessage)
         {
             var root = FindOrCreateRootGrid();
             var uniqueName = GameObjectUtility.GetUniqueNameForSibling(root.transform, "Tilemap");
@@ -108,12 +121,16 @@ internal static void CreateIsometricTilemap()
             tilemapGO.transform.position = Vector3.zero;
 
             var grid = root.GetComponent<Grid>();
-            grid.cellLayout = Grid.CellLayout.Isometric;
-            grid.cellSize = new Vector3(1.0f, 0.5f, 0.0f);
+            // Case 1071703: Do not reset cell size if adding a new Tilemap to an existing Grid of the same layout
+            if (isometricLayout != grid.cellLayout)
+            {
+                grid.cellLayout = isometricLayout;
+                grid.cellSize = new Vector3(1.0f, 0.5f, 0.0f);
+            }
 
             var tilemapRenderer = tilemapGO.GetComponent<TilemapRenderer>();
             tilemapRenderer.sortOrder = TilemapRenderer.SortOrder.TopRight;
-            Undo.RegisterCreatedObjectUndo(tilemapGO, "Create Isometric Tilemap");
+            Undo.RegisterCreatedObjectUndo(tilemapGO, undoMessage);
         }
 
         private static void CreateHexagonalTilemap(GridLayout.CellSwizzle swizzle, string undoMessage)
diff --git a/Modules/TreeEditor/TreeEditor.cs b/Modules/TreeEditor/TreeEditor.cs
index 23a43f22f9..8ee5d00614 100644
--- a/Modules/TreeEditor/TreeEditor.cs
+++ b/Modules/TreeEditor/TreeEditor.cs
@@ -310,8 +310,6 @@ static void CreateNewTree(MenuCommand menuCommand)
             AssetDatabase.AddObjectToAsset(materialCutoutAsset, prefabAsset);
             AssetDatabase.AddObjectToAsset(data, prefabAsset);
 
-            PrefabUtility.ApplyPrefabInstance(prefabInstance);
-
             GameObjectUtility.SetParentAndAlign(prefabInstance, menuCommand.context as GameObject);
 
             // Store Creation undo
diff --git a/Modules/UnityEditorAnalyticsEditor/EditorAnalytics.bindings.cs b/Modules/UnityEditorAnalyticsEditor/EditorAnalytics.bindings.cs
index 5bd23f2bf8..56e7db50de 100644
--- a/Modules/UnityEditorAnalyticsEditor/EditorAnalytics.bindings.cs
+++ b/Modules/UnityEditorAnalyticsEditor/EditorAnalytics.bindings.cs
@@ -83,6 +83,8 @@ internal static bool SendCollabOperation(object parameters)
             return EditorAnalytics.SendEvent("collabOperation", parameters);
         }
 
+        internal extern static bool SendAssetDownloadEvent(object parameters);
+
         public extern static bool enabled
         {
             get;
diff --git a/Modules/UnityWebRequestAudio/Public/DownloadHandlerAudio.bindings.cs b/Modules/UnityWebRequestAudio/Public/DownloadHandlerAudio.bindings.cs
index dbc8c4accb..75c3447496 100644
--- a/Modules/UnityWebRequestAudio/Public/DownloadHandlerAudio.bindings.cs
+++ b/Modules/UnityWebRequestAudio/Public/DownloadHandlerAudio.bindings.cs
@@ -40,6 +40,7 @@ protected override string GetText()
             throw new System.NotSupportedException("String access is not supported for audio clips");
         }
 
+        [NativeThrows]
         public extern AudioClip audioClip { get; }
 
         public extern bool streamAudio { get; set; }
diff --git a/Modules/XR/ScriptBindings/XRInput.bindings.cs b/Modules/XR/ScriptBindings/XRInput.bindings.cs
index 461c5f7a68..b836986d97 100644
--- a/Modules/XR/ScriptBindings/XRInput.bindings.cs
+++ b/Modules/XR/ScriptBindings/XRInput.bindings.cs
@@ -20,13 +20,11 @@ public struct HapticCapabilities : IEquatable<HapticCapabilities>
         bool m_SupportsImpulse;
         bool m_SupportsBuffer;
         uint m_BufferFrequencyHz;
-        uint m_BufferMaxSize;
 
         public uint numChannels             { get { return m_NumChannels; }         internal set { m_NumChannels = value; } }
         public bool supportsImpulse         { get { return m_SupportsImpulse; }     internal set { m_SupportsImpulse = value; } }
         public bool supportsBuffer          { get { return m_SupportsBuffer; }      internal set { m_SupportsBuffer = value; } }
         public uint bufferFrequencyHz       { get { return m_BufferFrequencyHz; }   internal set { m_BufferFrequencyHz = value; } }
-        public uint bufferMaxSize           { get { return m_BufferMaxSize; }       internal set { m_BufferMaxSize = value; } }
 
         public override bool Equals(object obj)
         {
@@ -41,8 +39,7 @@ public bool Equals(HapticCapabilities other)
             return numChannels == other.numChannels &&
                 supportsImpulse == other.supportsImpulse &&
                 supportsBuffer == other.supportsBuffer &&
-                bufferFrequencyHz == other.bufferFrequencyHz &&
-                bufferMaxSize == other.bufferMaxSize;
+                bufferFrequencyHz == other.bufferFrequencyHz;
         }
 
         public override int GetHashCode()
@@ -50,68 +47,78 @@ public override int GetHashCode()
             return numChannels.GetHashCode() ^
                 (supportsImpulse.GetHashCode() << 1) ^
                 (supportsBuffer.GetHashCode() >> 1) ^
-                (bufferFrequencyHz.GetHashCode() << 2) ^
-                (bufferMaxSize.GetHashCode() >> 2);
+                (bufferFrequencyHz.GetHashCode() << 2);
+        }
+
+        public static bool operator==(HapticCapabilities a, HapticCapabilities b)
+        {
+            return a.Equals(b);
+        }
+
+        public static bool operator!=(HapticCapabilities a, HapticCapabilities b)
+        {
+            return !(a == b);
         }
     }
 
+    [UsedByNativeCode]
     [StructLayout(LayoutKind.Sequential)]
     [NativeConditional("ENABLE_VR")]
-    public struct HapticState : IEquatable<HapticState>
+    [NativeHeader("Modules/XR/Subsystems/Input/Public/XRInputTrackingFacade.h")]
+    public struct InputDevice : IEquatable<InputDevice>
     {
-        uint m_SamplesQueued;
-        uint m_SamplesAvailable;
+        private UInt64 m_DeviceId;
 
-        public uint samplesQueued { get { return m_SamplesQueued; } internal set { m_SamplesQueued = value; } }
-        public uint samplesAvailable { get { return m_SamplesAvailable; } internal set { m_SamplesAvailable = value; } }
+        internal InputDevice(UInt64 deviceId) { m_DeviceId = deviceId; }
+
+        public bool IsValid { get { return InputTracking.IsDeviceValid(m_DeviceId); } }
+
+        // Haptics
+        public bool SendHapticImpulse(uint channel, float amplitude, float duration = 1.0f)     { return InputTracking.SendHapticImpulse(m_DeviceId, channel, amplitude, duration); }
+        public bool SendHapticBuffer(uint channel, byte[] buffer)                               { return InputTracking.SendHapticBuffer(m_DeviceId, channel, buffer); }
+        public bool TryGetHapticCapabilities(out HapticCapabilities capabilities)               { return InputTracking.TryGetHapticCapabilities(m_DeviceId, out capabilities); }
+        public void StopHaptics()                                                               { InputTracking.StopHaptics(m_DeviceId); }
 
         public override bool Equals(object obj)
         {
-            if (!(obj is HapticState))
+            if (!(obj is InputDevice))
                 return false;
 
-            return Equals((HapticState)obj);
+            return Equals((InputDevice)obj);
         }
 
-        public bool Equals(HapticState other)
+        public bool Equals(InputDevice other)
         {
-            return samplesQueued == other.samplesQueued &&
-                samplesAvailable == other.samplesAvailable;
+            return m_DeviceId == other.m_DeviceId;
         }
 
         public override int GetHashCode()
         {
-            return samplesQueued.GetHashCode() ^ (samplesAvailable.GetHashCode() << 2);
+            return m_DeviceId.GetHashCode();
+        }
+
+        public static bool operator==(InputDevice a, InputDevice b)
+        {
+            return a.Equals(b);
+        }
+
+        public static bool operator!=(InputDevice a, InputDevice b)
+        {
+            return !(a == b);
         }
     }
 
     [NativeHeader("Modules/XR/Subsystems/Input/Public/XRInputTrackingFacade.h")]
     [NativeConditional("ENABLE_VR")]
     [StaticAccessor("XRInputTrackingFacade::Get()", StaticAccessorType.Dot)]
-    public partial class InputHaptic
+    public partial class InputDevices
     {
-        [NativeConditional("ENABLE_VR")]
-        bool SendImpulse(XRNode node, uint channel, float amplitude) { return SendImpulse(node, channel, amplitude, 1.0f); }
-
-        [NativeConditional("ENABLE_VR")]
-        [NativeMethod("SendHapticImpulse")]
-        extern public static bool SendImpulse(XRNode node, uint channel, float amplitude, [UnityEngine.Internal.DefaultValue("1.0f")] float frequency);
-
-        [NativeConditional("ENABLE_VR")]
-        [NativeMethod("SendHapticBuffer")]
-        extern public static bool SendBuffer(XRNode node, uint channel, byte[] buffer);
-
-        [NativeConditional("ENABLE_VR", "false")]
-        [NativeMethod("TryGetHapticCapabilities")]
-        extern public static bool TryGetCapabilities(XRNode node, out HapticCapabilities capabilities);
-
-        [NativeConditional("ENABLE_VR", "false")]
-        [NativeMethod("TryGetHapticState")]
-        extern public static bool TryGetState(XRNode node, out HapticState state);
-
-        [NativeConditional("ENABLE_VR")]
-        [NativeMethod("StopHaptics")]
-        extern public static void Stop(XRNode node);
+        [NativeConditional("ENABLE_VR", "InputDevice::Identity")]
+        public static InputDevice GetDeviceAtXRNode(XRNode node)
+        {
+            UInt64 deviceId = InputTracking.GetDeviceIdAtXRNode(node);
+            return new InputDevice(deviceId);
+        }
     }
 
     [NativeHeader("Modules/XR/Subsystems/Input/Public/XRInputTrackingFacade.h")]
@@ -156,5 +163,13 @@ extern public static bool disablePositionalTracking
             [NativeName("SetPositionalTrackingDisabled")]
             set;
         }
+
+        internal static extern bool SendHapticImpulse(UInt64 deviceId, uint channel, float amplitude, float duration);
+        internal static extern bool SendHapticBuffer(UInt64 deviceId, uint channel, byte[] buffer);
+        internal static extern bool TryGetHapticCapabilities(UInt64 deviceId, out HapticCapabilities capabilities);
+        internal static extern void StopHaptics(UInt64 deviceId);
+
+        internal static extern bool IsDeviceValid(UInt64 deviceId);
+        internal static extern UInt64 GetDeviceIdAtXRNode(XRNode node);
     }
 }
diff --git a/README.md b/README.md
index b8559e74df..f414498bbd 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-## Unity 2018.3.0a11 C# reference source code
+## Unity 2018.3.0b1 C# reference source code
 
 The C# part of the Unity engine and editor source code.
 May be used for reference purposes only.
diff --git a/Runtime/Export/Camera.bindings.cs b/Runtime/Export/Camera.bindings.cs
index a34e8b2ccf..c27dd8219c 100644
--- a/Runtime/Export/Camera.bindings.cs
+++ b/Runtime/Export/Camera.bindings.cs
@@ -274,7 +274,7 @@ public bool RenderToCubemap(RenderTexture cubemap, int faceMask, MonoOrStereosco
 
         public void AddCommandBuffer(CameraEvent evt, CommandBuffer buffer)
         {
-            if (!Enum.IsDefined(typeof(CameraEvent), evt))
+            if (!Rendering.CameraEventUtils.IsValid(evt))
                 throw new ArgumentException(string.Format(@"Invalid CameraEvent value ""{0}"".", (int)evt), "evt");
             if (buffer == null) throw new NullReferenceException("buffer is null");
             AddCommandBufferImpl(evt, buffer);
@@ -282,7 +282,7 @@ public void AddCommandBuffer(CameraEvent evt, CommandBuffer buffer)
 
         public void AddCommandBufferAsync(CameraEvent evt, CommandBuffer buffer, ComputeQueueType queueType)
         {
-            if (!Enum.IsDefined(typeof(CameraEvent), evt))
+            if (!Rendering.CameraEventUtils.IsValid(evt))
                 throw new ArgumentException(string.Format(@"Invalid CameraEvent value ""{0}"".", (int)evt), "evt");
             if (buffer == null) throw new NullReferenceException("buffer is null");
             AddCommandBufferAsyncImpl(evt, buffer, queueType);
@@ -290,7 +290,7 @@ public void AddCommandBufferAsync(CameraEvent evt, CommandBuffer buffer, Compute
 
         public void RemoveCommandBuffer(CameraEvent evt, CommandBuffer buffer)
         {
-            if (!Enum.IsDefined(typeof(CameraEvent), evt))
+            if (!Rendering.CameraEventUtils.IsValid(evt))
                 throw new ArgumentException(string.Format(@"Invalid CameraEvent value ""{0}"".", (int)evt), "evt");
             if (buffer == null) throw new NullReferenceException("buffer is null");
             RemoveCommandBufferImpl(evt, buffer);
diff --git a/Runtime/Export/GI/DynamicGI.bindings.cs b/Runtime/Export/GI/DynamicGI.bindings.cs
index 04a31065e6..b4e134a2a3 100644
--- a/Runtime/Export/GI/DynamicGI.bindings.cs
+++ b/Runtime/Export/GI/DynamicGI.bindings.cs
@@ -12,10 +12,13 @@ public sealed partial class DynamicGI
     {
         public static float indirectScale { get { return 0.0f; } set {} }
         public static float updateThreshold { get { return 0.0f; } set {} }
+        public static int   materialUpdateTimeSlice { get { return 0; } set {} }
         public static void  SetEmissive(Renderer renderer, Color color) {}
         public static void  SetEnvironmentData(float[] input) {}
         public static bool  synchronousMode { get { return false; } set {} }
         public static bool  isConverged { get { return false; } }
+
+        internal static int scheduledMaterialUpdatesCount { get { return 0; } }
         public static extern void UpdateEnvironment();
 
         [System.ComponentModel.EditorBrowsable(System.ComponentModel.EditorBrowsableState.Never)]
diff --git a/Runtime/Export/GraphicsEnums.cs b/Runtime/Export/GraphicsEnums.cs
index 1546184f20..b1ac63f5e6 100644
--- a/Runtime/Export/GraphicsEnums.cs
+++ b/Runtime/Export/GraphicsEnums.cs
@@ -961,6 +961,17 @@ public enum CameraEvent
         AfterHaloAndLensFlares
     }
 
+    internal static class CameraEventUtils
+    {
+        const CameraEvent k_MinimumValue = CameraEvent.BeforeDepthTexture;
+        const CameraEvent k_MaximumValue = CameraEvent.AfterHaloAndLensFlares;
+
+        public static bool IsValid(CameraEvent value)
+        {
+            return value >= k_MinimumValue && value <= k_MaximumValue;
+        }
+    }
+
     // Keep in sync with RenderLightEventType in Runtime/Graphics/CommandBuffer/RenderingEvents.h
     public enum LightEvent
     {
diff --git a/Runtime/Export/SystemInfo.bindings.cs b/Runtime/Export/SystemInfo.bindings.cs
index 6125bb74a1..23fa6dc4ed 100644
--- a/Runtime/Export/SystemInfo.bindings.cs
+++ b/Runtime/Export/SystemInfo.bindings.cs
@@ -214,6 +214,11 @@ public static bool graphicsMultiThreaded
             get { return GetGraphicsMultiThreaded(); }
         }
 
+        public static bool hasHiddenSurfaceRemovalOnGPU
+        {
+            get { return HasHiddenSurfaceRemovalOnGPU(); }
+        }
+
         // Are built-in shadows supported? (RO)
         public static bool supportsShadows
         {
@@ -527,6 +532,9 @@ public static int graphicsPixelFillrate
         [FreeFunction("ScriptingGraphicsCaps::GetGraphicsMultiThreaded")]
         static extern bool GetGraphicsMultiThreaded();
 
+        [FreeFunction("ScriptingGraphicsCaps::HasHiddenSurfaceRemovalOnGPU")]
+        static extern bool HasHiddenSurfaceRemovalOnGPU();
+
         [FreeFunction("ScriptingGraphicsCaps::SupportsShadows")]
         static extern bool SupportsShadows();
 
diff --git a/Runtime/Export/Vector3Int.cs b/Runtime/Export/Vector3Int.cs
index d7871a42a8..15e21aa1f8 100644
--- a/Runtime/Export/Vector3Int.cs
+++ b/Runtime/Export/Vector3Int.cs
@@ -177,7 +177,9 @@ public bool Equals(Vector3Int other)
 
         public override int GetHashCode()
         {
-            return x.GetHashCode() ^ (y.GetHashCode() << 2) ^ (z.GetHashCode() >> 2);
+            var yHash = y.GetHashCode();
+            var zHash = z.GetHashCode();
+            return x.GetHashCode() ^ (yHash << 4) ^ (yHash >> 28) ^ (zHash >> 4) ^ (zHash << 28);
         }
 
         public override string ToString()
diff --git a/Runtime/Networking/Managed/MatchMakingClient.cs b/Runtime/Networking/Managed/MatchMakingClient.cs
index 79df91f44d..4725689b0a 100644
--- a/Runtime/Networking/Managed/MatchMakingClient.cs
+++ b/Runtime/Networking/Managed/MatchMakingClient.cs
@@ -12,6 +12,7 @@ namespace UnityEngine.Networking.Match
 {
     // returned when you create or join a match (private info)
     //[Serializable] //TODO: enabled this when 64 bit enum issue is resolved
+    [Obsolete("The matchmaker and relay feature will be removed in the future, minimal support will continue until this can be safely done.")]
     public class MatchInfo
     {
         public string address { get; private set; }
@@ -53,6 +54,7 @@ public override string ToString()
         }
     }
 
+    [Obsolete("The matchmaker and relay feature will be removed in the future, minimal support will continue until this can be safely done.")]
     public class MatchInfoSnapshot
     {
         public NetworkID networkId { get; private set; }
@@ -109,6 +111,7 @@ internal MatchInfoSnapshot(MatchDesc matchDesc)
         }
     }
 
+    [Obsolete("The matchmaker and relay feature will be removed in the future, minimal support will continue until this can be safely done.")]
     public class NetworkMatch : MonoBehaviour
     {
         public delegate void BasicResponseDelegate(bool success, string extendedInfo);
@@ -137,11 +140,9 @@ public Coroutine CreateMatch(string matchName, uint matchSize, bool matchAdverti
                 Debug.LogError("Matchmaking is not supported on WebGL player.");
                 return null;
             }
-            else
-                return CreateMatch(new CreateMatchRequest { name = matchName, size = matchSize, advertise = matchAdvertise, password = matchPassword, publicAddress = publicClientAddress, privateAddress = privateClientAddress, eloScore = eloScoreForMatch, domain = requestDomain }, callback);
+            return CreateMatch(new CreateMatchRequest { name = matchName, size = matchSize, advertise = matchAdvertise, password = matchPassword, publicAddress = publicClientAddress, privateAddress = privateClientAddress, eloScore = eloScoreForMatch, domain = requestDomain }, callback);
         }
 
-        // Begin Create a match
         internal Coroutine CreateMatch(CreateMatchRequest req, DataResponseDelegate<MatchInfo> callback)
         {
             if (callback == null)
diff --git a/Runtime/Networking/Managed/NetworkTransportConfig.cs b/Runtime/Networking/Managed/NetworkTransportConfig.cs
index 9bdf9f3b57..84450263db 100644
--- a/Runtime/Networking/Managed/NetworkTransportConfig.cs
+++ b/Runtime/Networking/Managed/NetworkTransportConfig.cs
@@ -68,6 +68,7 @@ public enum ConnectionAcksType
     };
 
     [Serializable]
+    [Obsolete("The UNET transport will be removed in the future as soon a replacement is ready.")]
     public class ChannelQOS
     {
         [SerializeField]
@@ -105,6 +106,7 @@ public ChannelQOS(ChannelQOS channel)
     //to allow user manipulate channel info via property with parameter (using array interface)
     //all fields are defined for direct access from HLAPI (it it needed)
     [Serializable]
+    [Obsolete("The UNET transport will be removed in the future as soon a replacement is ready.")]
     public class ConnectionConfig
     {
         private  const int g_MinPacketSize = 128;
@@ -502,6 +504,7 @@ public IList<byte> GetSharedOrderChannels(byte idx)
     //and array of special connection (with special configuration)
     //AddSpecialConnection will return connection id which user should use when he call connect to identify special configuration for this connection
     [Serializable]
+    [Obsolete("The UNET transport will be removed in the future as soon a replacement is ready.")]
     public class HostTopology
     {
         [SerializeField]
@@ -589,6 +592,7 @@ public int AddSpecialConnectionConfig(ConnectionConfig config)
     }
 
     [Serializable]
+    [Obsolete("The UNET transport will be removed in the future as soon a replacement is ready.")]
     public class GlobalConfig
     {
         private const uint g_MaxTimerTimeout = 12000;         //before changing check UNETConfiguration.h file
@@ -753,6 +757,7 @@ public Action<int, int> ConnectionReadyForSend
         }
     }
 
+    [Obsolete("The UNET transport will be removed in the future as soon a replacement is ready.")]
     public class ConnectionSimulatorConfig : IDisposable
     {
         internal int m_OutMinDelay;
diff --git a/Runtime/Networking/ScriptBindings/UNETTransportConfig.bindings.cs b/Runtime/Networking/ScriptBindings/UNETTransportConfig.bindings.cs
index a170c1b9ed..10e043cef8 100644
--- a/Runtime/Networking/ScriptBindings/UNETTransportConfig.bindings.cs
+++ b/Runtime/Networking/ScriptBindings/UNETTransportConfig.bindings.cs
@@ -13,6 +13,7 @@
 
 namespace UnityEngine.Networking
 {
+#pragma warning disable 618
 
     [NativeHeader("Runtime/Networking/UNETManager.h")]
     [NativeHeader("Runtime/Networking/UNetTypes.h")]
@@ -308,4 +309,5 @@ public void Dispose()
         [NativeProperty("m_MaxNetSimulatorTimeout", TargetType.Field)] private extern uint MaxNetSimulatorTimeout { set; }
     }
 
+#pragma warning restore 618
 }
diff --git a/Runtime/Networking/ScriptBindings/UNETworking.bindings.cs b/Runtime/Networking/ScriptBindings/UNETworking.bindings.cs
index c5eafd5400..0d8523ddf3 100644
--- a/Runtime/Networking/ScriptBindings/UNETworking.bindings.cs
+++ b/Runtime/Networking/ScriptBindings/UNETworking.bindings.cs
@@ -19,6 +19,7 @@ namespace UnityEngine.Networking
     [NativeHeader("Runtime/Networking/UNetTypes.h")]
     [NativeHeader("Runtime/Networking/UNETConfiguration.h")]
     [NativeConditional("ENABLE_NETWORK && ENABLE_UNET", true)]
+    [Obsolete("The UNET transport will be removed in the future as soon a replacement is ready.")]
     public sealed partial class NetworkTransport
     {
         private NetworkTransport() {}
diff --git a/Runtime/Profiler/ScriptBindings/MemoryProfiling.bindings.cs b/Runtime/Profiler/ScriptBindings/MemoryProfiling.bindings.cs
index dc9144cefa..38177b0d47 100644
--- a/Runtime/Profiler/ScriptBindings/MemoryProfiling.bindings.cs
+++ b/Runtime/Profiler/ScriptBindings/MemoryProfiling.bindings.cs
@@ -61,6 +61,7 @@ public static void TakeTempSnapshot(Action<string, bool>  finishCallback, Captur
             TakeSnapshot(path, finishCallback, captureFlags);
         }
 
+        [RequiredByNativeCode]
         static byte[] PrepareMetadata()
         {
             if (createMetaData == null)
@@ -71,6 +72,9 @@ static byte[] PrepareMetadata()
             MetaData data = new MetaData();
             createMetaData(data);
 
+            if (data.content == null) data.content = "";
+            if (data.platform == null) data.platform = "";
+
             int contentLength = sizeof(char) * data.content.Length;
             int platformLength = sizeof(char) * data.platform.Length;
 
@@ -164,6 +168,7 @@ private static int WriteStringToByteArray(byte[] array, int offset, string value
             return offset;
         }
 
+        [RequiredByNativeCode]
         static void FinalizeSnapshot(string path, bool result)
         {
             if (snapshotFinished != null)