diff --git a/ui/modules/api.ts b/ui/modules/api.ts
index bac8828c58..cd1939c5a9 100644
--- a/ui/modules/api.ts
+++ b/ui/modules/api.ts
@@ -307,6 +307,14 @@ export function setAuthHeader(forDevOps) {
   }
 }
 
+function showDittoError(dittoErr, response) {
+  if (dittoErr.status && dittoErr.message) {
+    Utils.showError(dittoErr.description + `\n(${dittoErr.error})`, dittoErr.message, dittoErr.status);
+  } else {
+    Utils.showError(JSON.stringify(dittoErr), 'Error', response.status);
+  }
+}
+
 /**
  * Calls the Ditto api
  * @param {String} method 'POST', 'GET', 'DELETE', etc.
@@ -315,10 +323,16 @@ export function setAuthHeader(forDevOps) {
  * @param {Object} additionalHeaders object with additional header fields
  * @param {boolean} returnHeaders request full response instead of json content
  * @param {boolean} devOps default: false. Set true to avoid /api/2 path
+ * @param {boolean} returnErrorJson default: false. Set true to return the response of a failed HTTP call as JSON
  * @return {Object} result as json object
  */
-export async function callDittoREST(method, path, body = null,
-    additionalHeaders = null, returnHeaders = false, devOps = false): Promise<any> {
+export async function callDittoREST(method,
+                                    path,
+                                    body = null,
+                                    additionalHeaders = null,
+                                    returnHeaders = false,
+                                    devOps = false,
+                                    returnErrorJson = false): Promise<any> {
   let response;
   const contentType = method === 'PATCH' ? 'application/merge-patch+json' : 'application/json';
   try {
@@ -336,14 +350,25 @@ export async function callDittoREST(method, path, body = null,
     throw err;
   }
   if (!response.ok) {
-    response.json()
+    if (returnErrorJson) {
+      if (returnHeaders) {
+        return response;
+      } else {
+        return response.json().then((dittoErr) => {
+          showDittoError(dittoErr, response);
+          return dittoErr;
+        });
+      }
+    } else {
+      response.json()
         .then((dittoErr) => {
-          Utils.showError(dittoErr.description + `\n(${dittoErr.error})`, dittoErr.message, dittoErr.status);
+          showDittoError(dittoErr, response);
         })
         .catch((err) => {
           Utils.showError('No error details from Ditto', response.statusText, response.status);
         });
-    throw new Error('An error occurred: ' + response.status);
+      throw new Error('An error occurred: ' + response.status);
+    }
   }
   if (response.status !== 204) {
     if (returnHeaders) {
@@ -409,7 +434,7 @@ export async function callConnectionsAPI(operation, successCallback, connectionI
   if (!response.ok) {
     response.json()
         .then((dittoErr) => {
-          Utils.showError(dittoErr.description, dittoErr.message, dittoErr.status);
+          showDittoError(dittoErr, response);
         })
         .catch((err) => {
           Utils.showError('No error details from Ditto', response.statusText, response.status);
@@ -422,7 +447,7 @@ export async function callConnectionsAPI(operation, successCallback, connectionI
         .then((data) => {
           if (data && data['?'] && data['?']['?'].status >= 400) {
             const dittoErr = data['?']['?'].payload;
-            Utils.showError(dittoErr.description, dittoErr.message, dittoErr.status);
+            showDittoError(dittoErr, response);
           } else {
             if (params.unwrapJsonPath) {
               params.unwrapJsonPath.split('.').forEach(function(node) {
diff --git a/ui/modules/things/featureMessages.ts b/ui/modules/things/featureMessages.ts
index 5aec47f7f5..9e38d878e7 100644
--- a/ui/modules/things/featureMessages.ts
+++ b/ui/modules/things/featureMessages.ts
@@ -124,10 +124,14 @@ function messageFeature() {
   }
   aceResponse.setValue('');
   API.callDittoREST('POST', '/things/' + Things.theThing.thingId +
-      '/features/' + theFeatureId +
-      '/inbox/messages/' + dom.inputMessageSubject.value +
-      '?timeout=' + dom.inputMessageTimeout.value,
-  payload,
+    '/features/' + theFeatureId +
+    '/inbox/messages/' + dom.inputMessageSubject.value +
+    '?timeout=' + dom.inputMessageTimeout.value,
+    payload,
+    null,
+    false,
+    false,
+    true
   ).then((data) => {
     dom.buttonMessageSend.classList.remove('busy');
     dom.buttonMessageSend.disabled = false;
@@ -137,7 +141,7 @@ function messageFeature() {
   }).catch((err) => {
     dom.buttonMessageSend.classList.remove('busy');
     dom.buttonMessageSend.disabled = false;
-    aceResponse.setValue('');
+    aceResponse.setValue(`Error: ${err}`);
   });
 }
 
diff --git a/ui/modules/things/thingMessages.ts b/ui/modules/things/thingMessages.ts
index 1de988d521..bb04418405 100644
--- a/ui/modules/things/thingMessages.ts
+++ b/ui/modules/things/thingMessages.ts
@@ -117,9 +117,13 @@ function messageThing() {
   }
   aceResponse.setValue('');
   API.callDittoREST('POST', '/things/' + Things.theThing.thingId +
-      '/inbox/messages/' + dom.inputThingMessageSubject.value +
-      '?timeout=' + dom.inputThingMessageTimeout.value,
-  payload,
+    '/inbox/messages/' + dom.inputThingMessageSubject.value +
+    '?timeout=' + dom.inputThingMessageTimeout.value,
+    payload,
+    null,
+    false,
+    false,
+    true
   ).then((data) => {
     dom.buttonThingMessageSend.classList.remove('busy');
     dom.buttonThingMessageSend.disabled = false;
@@ -129,7 +133,7 @@ function messageThing() {
   }).catch((err) => {
     dom.buttonThingMessageSend.classList.remove('busy');
     dom.buttonThingMessageSend.disabled = false;
-    aceResponse.setValue('');
+    aceResponse.setValue(`Error: ${err}`);
   });
 }