diff --git a/toolbox/core/bst_memory.m b/toolbox/core/bst_memory.m
index 245b3f1e1..b4995b66a 100644
--- a/toolbox/core/bst_memory.m
+++ b/toolbox/core/bst_memory.m
@@ -795,9 +795,6 @@ function LoadChannelFile(iDS, ChannelFile)
     GlobalData.DataSet(iDS).DataFile    = file_short(DataFile);
     GlobalData.DataSet(iDS).Measures    = Measures;
     
-    % ===== LOAD CHANNEL FILE =====
-    LoadChannelFile(iDS, ChannelFile);
-    
     % ===== Check time window consistency with previously loaded data =====
     if isTimeCheck
         % Update time window
@@ -814,25 +811,18 @@ function LoadChannelFile(iDS, ChannelFile)
                 return;
             % Otherwise: unload all the other datasets
             else
-                % Save newly created dataset
-                bakDS = GlobalData.DataSet(iDS);
-                % Unload everything
-                UnloadAll('Forced');
-                % If not everything was unloaded correctly (eg. the user cancelled half way when asked to save the modifications)
-                if ~isempty(GlobalData.DataSet)
-                    % Unload the new dataset
-                    UnloadDataSets(iDS);
-                    iDS = [];
-                    return;
+                iDS = UnloadOtherDs(iDS);
+                if isempty(iDS)
+                    return
                 end
-                % Restore new dataset
-                GlobalData.DataSet = bakDS;
-                iDS = 1;
                 % Update time window
                 isTimeCoherent = CheckTimeWindows();
             end
         end
     end
+
+    % ===== LOAD CHANNEL FILE =====
+    LoadChannelFile(iDS, ChannelFile);
     
     % ===== UPDATE TOOL TABS =====
     if ~isempty(iDS) && strcmpi(GlobalData.DataSet(iDS).Measures.DataType, 'raw')
@@ -1251,14 +1241,24 @@ function ReloadStatDataSets() %#ok<DEFNU>
         isTimeCoherent = CheckTimeWindows();
         % If loaded results are not coherent with previous data
         if ~isTimeCoherent
-            % Remove it
-            GlobalData.DataSet(iDS).Results(iResult) = [];
-            iDS = [];
-            iResult  = [];
-            bst_error(['Time definition for this file is not compatible with the other files' 10 ...
-                       'already loaded in Brainstorm.' 10 10 ...
-                       'Close existing windows before opening this file, or use the Navigator.'], 'Load results', 0);
-            return
+            res = java_dialog('question', [...
+                'The time definition is not compatible with previously loaded files.' 10 ...
+                'Unload all the other files first?' 10 10], 'Load results', [], {'Unload other files', 'Cancel'});
+            % Cancel: Unload the new dataset
+            if isempty(res) || strcmpi(res, 'Cancel')
+                UnloadDataSets(iDS);
+                iDS = [];
+                return;
+            % Otherwise: unload all the other datasets
+            else
+                iDS = UnloadOtherDs(iDS);
+                if isempty(iDS)
+                    iResult = [];
+                    return
+                end
+                % Update time window
+                isTimeCoherent = CheckTimeWindows();
+            end
         end
     end
     % Update TimeWindow panel, if it exists
@@ -1982,13 +1982,31 @@ function LoadResultsMatrix(iDS, iResult)
     if isempty(iDS) && isempty(Mat.Events)
         iDS = GetDataSetStudy(sStudy.FileName);
     end
-    % Create dataset
-    if isempty(iDS)
+    % Check time against existing DS
+    isTimeOkDs = 1;
+    if ~isempty(iDS) && (length(Mat.Time) >= 2)
+        % Save measures information if no DataFile is available
+        if isempty(GlobalData.DataSet(iDS).Measures) || isempty(GlobalData.DataSet(iDS).Measures.Time)
+            GlobalData.DataSet(iDS).Measures.Time            = double(Mat.Time([1, end]));
+            GlobalData.DataSet(iDS).Measures.SamplingRate    = double(Mat.Time(2) - Mat.Time(1));
+            GlobalData.DataSet(iDS).Measures.NumberOfSamples = length(Mat.Time);
+        elseif (abs(Mat.Time(1)   - GlobalData.DataSet(iDS).Measures.Time(1)) > 1e-5) || ...
+               (abs(Mat.Time(end) - GlobalData.DataSet(iDS).Measures.Time(2)) > 1e-5) || ...
+               ~isequal(length(Mat.Time), GlobalData.DataSet(iDS).Measures.NumberOfSamples)
+            isTimeOkDs = 0;
+        end
+    end
+    % Create dataset if not existent or different time definition
+    if isempty(iDS) || ~isTimeOkDs
         % Create a new DataSet only for results
         iDS = length(GlobalData.DataSet) + 1;
         GlobalData.DataSet(iDS)             = db_template('DataSet');
         GlobalData.DataSet(iDS).SubjectFile = file_short(sStudy.BrainStormSubject);
         GlobalData.DataSet(iDS).StudyFile   = file_short(sStudy.FileName);
+        % Save measures information
+        GlobalData.DataSet(iDS).Measures.Time            = double(Mat.Time([1, end]));
+        GlobalData.DataSet(iDS).Measures.SamplingRate    = double(Mat.Time(2) - Mat.Time(1));
+        GlobalData.DataSet(iDS).Measures.NumberOfSamples = length(Mat.Time);
     end
     % Make sure that there is only one dataset selected
     iDS = iDS(1);
@@ -1996,26 +2014,28 @@ function LoadResultsMatrix(iDS, iResult)
     % ===== CHECK TIME =====
     % If there time in this file
     if (length(Mat.Time) >= 2)
-        isTimeOkDs = 1;
-        % Save measures information if no DataFile is available
-        if isempty(GlobalData.DataSet(iDS).Measures) || isempty(GlobalData.DataSet(iDS).Measures.Time)
-            GlobalData.DataSet(iDS).Measures.Time            = double(Mat.Time([1, end])); 
-            GlobalData.DataSet(iDS).Measures.SamplingRate    = double(Mat.Time(2) - Mat.Time(1));
-            GlobalData.DataSet(iDS).Measures.NumberOfSamples = length(Mat.Time);
-        elseif (abs(Mat.Time(1)   - GlobalData.DataSet(iDS).Measures.Time(1)) > 1e-5) || ...
-               (abs(Mat.Time(end) - GlobalData.DataSet(iDS).Measures.Time(2)) > 1e-5) || ...
-               ~isequal(length(Mat.Time), GlobalData.DataSet(iDS).Measures.NumberOfSamples)
-            isTimeOkDs = 0;
-        end
         % Update time window
         isTimeCoherent = CheckTimeWindows();
         % If loaded file are not coherent with previous data
         if ~isTimeCoherent || ~isTimeOkDs
-            iDS = [];
-            bst_error(['Time definition for this file is not compatible with the other files' 10 ...
-                       'already loaded in Brainstorm.' 10 10 ...
-                       'Close existing windows before opening this file, or use the Navigator.'], 'Load matrix', 0);
-            return
+            res = java_dialog('question', [...
+                'The time definition is not compatible with previously loaded files.' 10 ...
+                'Unload all the other files first?' 10 10], 'Load matrix', [], {'Unload other files', 'Cancel'});
+            % Cancel: Unload the new dataset
+            if isempty(res) || strcmpi(res, 'Cancel')
+                UnloadDataSets(iDS);
+                iDS = [];
+                return;
+            % Otherwise: unload all the other datasets
+            else
+                iDS = UnloadOtherDs(iDS);
+                if isempty(iDS)
+                    iMatrix = [];
+                    return
+                end
+                % Update time window
+                isTimeCoherent = CheckTimeWindows();
+            end
         end
         % Update TimeWindow panel
         panel_time('UpdatePanel');
@@ -3556,5 +3576,24 @@ function SaveChannelFile(iDS)
     end
 end
 
+%% ===== UNLOAD OTHER DS =====
+function iDS = UnloadOtherDs(iDS)
+% Unload Brainstorm datasets except for iDS. It returns the new iDS (iDS=1) for the kept DS
+    global GlobalData;
+    % Save dataset to keep
+    bakDS = GlobalData.DataSet(iDS);
+    % Unload everything
+    UnloadAll('Forced');
+    % If not everything was unloaded correctly (eg. the user cancelled half way when asked to save the modifications)
+    if ~isempty(GlobalData.DataSet)
+        % Unload also dataset to keep
+        UnloadDataSets(iDS);
+        iDS = [];
+        return;
+    end
+    % Restore dataset
+    GlobalData.DataSet = bakDS;
+    iDS = 1;
+end
 
 
diff --git a/toolbox/gui/view_surface_data.m b/toolbox/gui/view_surface_data.m
index 46d98dd6c..bcfdbfcf1 100644
--- a/toolbox/gui/view_surface_data.m
+++ b/toolbox/gui/view_surface_data.m
@@ -167,6 +167,9 @@
         iDS = bst_memory('GetDataSetSubject', sSubject.FileName, 1);
 end
 
+if isempty(iDS)
+    return;
+end
 
 %% ===== MODALITY =====
 if isempty(Modality)