diff --git a/SoObjects/Appointments/SOGoAppointmentObject.m b/SoObjects/Appointments/SOGoAppointmentObject.m
index 2e92b85aa..ad4153846 100644
--- a/SoObjects/Appointments/SOGoAppointmentObject.m
+++ b/SoObjects/Appointments/SOGoAppointmentObject.m
@@ -665,7 +665,7 @@
               else
                 {
                   iCalCalendar *calendar;
-                  NSDictionary *values;
+                  NSDictionary *values, *info;
                   NSString *reason;
                   iCalEvent *event;
 
@@ -682,8 +682,10 @@
 
                   reason = [values keysWithFormat: [self labelForKey: @"Maximum number of simultaneous bookings (%{NumberOfSimultaneousBookings}) reached for resource \"%{Cn} %{SystemEmail}\". The conflicting event is \"%{EventTitle}\", and starts on %{StartDate}."]];
 
+                  info = [NSDictionary dictionaryWithObject: reason forKey: @"reject"];
+
                   return [NSException exceptionWithHTTPStatus: 403
-                                                       reason: reason];
+                                                       reason: [info jsonRepresentation]];
                 }
             }
           //
diff --git a/UI/Templates/SchedulerUI/UIxAppointmentEditorTemplate.wox b/UI/Templates/SchedulerUI/UIxAppointmentEditorTemplate.wox
index 79666f52a..6a1427bc4 100644
--- a/UI/Templates/SchedulerUI/UIxAppointmentEditorTemplate.wox
+++ b/UI/Templates/SchedulerUI/UIxAppointmentEditorTemplate.wox
@@ -289,33 +289,32 @@
       </md-dialog-actions>
 
       <!-- attendee availability conflict -->
-      <md-dialog-actions class="md-default-theme md-bg md-warn"
-                         ng-show="editor.attendeeConflictError">
-        <div class="md-flex"><var:string label:value="A time conflict exists with one or more attendees.\nWould you like to keep the current settings anyway?"/></div>
-        <md-button class="md-icon-button" ng-click="editor.attendeeConflictError = false">
-          <md-icon label:aria-label="Close">close</md-icon>
-        </md-button>
-      </md-dialog-actions>
-      <md-dialog-actions class="md-default-theme md-bg md-warn"
-                         ng-show="editor.attendeeConflictError">
-          <div class="md-flex">
-            <md-icon>person</md-icon> {{editor.attendeeConflictError.attendee_name}} ({{editor.attendeeConflictError.attendee_email}})
+      <md-dialog-content class="md-default-theme md-bg md-warn md-padding sg-dialog-message ng-hide"
+                         ng-show="editor.attendeeConflictError.conflicts">
+        <div layout="row">
+          <div class="md-flex"><var:string label:value="A time conflict exists with one or more attendees.\nWould you like to keep the current settings anyway?"/></div>
+          <md-button class="md-icon-button" ng-click="editor.attendeeConflictError = false">
+            <md-icon label:aria-label="Close">close</md-icon>
+          </md-button>
+        </div>
+        <div class="md-flex" ng-show="editor.attendeeConflictError.attendee_email">
+          <md-icon>person</md-icon> {{editor.attendeeConflictError.attendee_name}} ({{editor.attendeeConflictError.attendee_email}})
+        </div>
+        <div layout="row"
+             ng-show="editor.attendeeConflictError.conflicts"
+             ng-repeat="conflict in editor.attendeeConflictError.conflicts">
+          <md-icon>schedule</md-icon>
+          <div class="pseudo-input-container">
+            <label class="pseudo-input-label"><var:string label:value="From"/></label>
+            <div>{{conflict.startDate}} <md-icon>trending_flat</md-icon></div>
+          </div>
+          <div class="pseudo-input-container md-flex">
+            <label class="pseudo-input-label"><var:string label:value="To"/></label>
+            <div>{{conflict.endDate}}</div>
           </div>
-      </md-dialog-actions>
-      <md-dialog-actions class="md-default-theme md-bg md-warn"
-                         ng-show="editor.attendeeConflictError"
-                         ng-repeat="conflict in editor.attendeeConflictError.conflicts">
-        <md-icon>schedule</md-icon>
-        <div class="pseudo-input-container">
-          <label class="pseudo-input-label"><var:string label:value="From"/></label>
-          <div>{{conflict.startDate}} <md-icon>trending_flat</md-icon></div>
         </div>
-        <div class="pseudo-input-container md-flex">
-          <label class="pseudo-input-label"><var:string label:value="To"/></label>
-          <div>{{conflict.endDate}}</div>
-        </div>
-      </md-dialog-actions>
-      <md-dialog-actions ng-show="editor.attendeeConflictError">
+      </md-dialog-content>
+      <md-dialog-actions ng-show="editor.attendeeConflictError.conflicts">
         <md-button type="button" ng-click="editor.cancel()">
           <var:string label:value="Cancel"/>
         </md-button>
@@ -329,6 +328,24 @@
           <var:string label:value="Save"/>
         </md-button>
       </md-dialog-actions>
+
+      <!-- rejected attendee invitation -->
+      <md-dialog-content class="md-default-theme md-bg md-warn md-padding sg-dialog-message ng-hide" layout="row"
+                         ng-show="editor.attendeeConflictError.reject">
+        <div class="md-flex">{{editor.attendeeConflictError.reject}}</div>
+        <md-button class="md-icon-button" ng-click="editor.attendeeConflictError = false">
+          <md-icon label:aria-label="Close">close</md-icon>
+        </md-button>
+      </md-dialog-content>
+      <md-dialog-actions ng-show="editor.attendeeConflictError.reject">
+        <md-button type="button" ng-click="editor.cancel()">
+          <var:string label:value="Cancel"/>
+        </md-button>
+        <md-button type="button"
+                   ng-click="editor.attendeeConflictError = false">
+          <var:string label:value="Edit"/>
+        </md-button>
+      </md-dialog-actions>
     </form>
   </md-dialog>
 </container>
diff --git a/UI/Templates/SchedulerUI/UIxCalMainView.wox b/UI/Templates/SchedulerUI/UIxCalMainView.wox
index d248c9486..3d11e4aca 100644
--- a/UI/Templates/SchedulerUI/UIxCalMainView.wox
+++ b/UI/Templates/SchedulerUI/UIxCalMainView.wox
@@ -740,8 +740,9 @@
   <!-- modal for attendee availability conflict -->
   <script type="text/ng-template" id="UIxAttendeeConflictDialog">
     <md-dialog flex="60" flex-xs="100">
-      <md-dialog-content class="md-dialog-content">
-        <h2 class="md-title">Warning</h2>
+      <md-dialog-content class="md-dialog-content"
+                         ng-show="$AttendeeConflictDialogController.conflictError.attendee_email">
+        <h2 class="md-title"><var:string label:value="Warning"/></h2>
         <p><var:string label:value="A time conflict exists with one or more attendees.\nWould you like to keep the current settings anyway?"/></p>
         <md-list>
           <md-list-item>
@@ -760,11 +761,17 @@
           </md-list-item>
         </md-list>
       </md-dialog-content>
+      <md-dialog-content class="md-dialog-content"
+                         ng-show="$AttendeeConflictDialogController.conflictError.reject">
+        <h2 class="md-title"><var:string label:value="Warning"/></h2>
+        <p>{{$AttendeeConflictDialogController.conflictError.reject}}</p>
+      </md-dialog-content>
       <md-dialog-actions>
         <md-button type="button" ng-click="$AttendeeConflictDialogController.cancel()">
           <var:string label:value="Cancel"/>
         </md-button>
         <md-button class="md-warn" type="button"
+                   ng-show="$AttendeeConflictDialogController.conflictError.conflicts"
                    ng-click="$AttendeeConflictDialogController.save()">
           <var:string label:value="Save"/>
         </md-button>
diff --git a/UI/WebServerResources/js/Scheduler/ComponentController.js b/UI/WebServerResources/js/Scheduler/ComponentController.js
index fc5f3df36..e5ab49775 100644
--- a/UI/WebServerResources/js/Scheduler/ComponentController.js
+++ b/UI/WebServerResources/js/Scheduler/ComponentController.js
@@ -227,9 +227,9 @@
             Alarm.getAlarms();
           }, function(response) {
             if (response.status == 403 &&
-                response.data && response.data.message && angular.isObject(response.data.message)) {
+                response.data && response.data.message &&
+                angular.isObject(response.data.message))
               vm.attendeeConflictError = response.data.message;
-            }
           });
       }
     }
diff --git a/UI/WebServerResources/scss/components/dialog/dialog.scss b/UI/WebServerResources/scss/components/dialog/dialog.scss
index f03da576a..415393a35 100644
--- a/UI/WebServerResources/scss/components/dialog/dialog.scss
+++ b/UI/WebServerResources/scss/components/dialog/dialog.scss
@@ -19,6 +19,22 @@ body.popup {
   }
 }
 
+md-dialog {
+  md-dialog-content {
+    &.sg-dialog-message {
+      // Prepare content to receive a "close" button on the right
+      align-items: flex-start;
+      display: flex;
+      flex-shrink: 0;
+      transition: background-color $swift-ease-in-duration $swift-ease-in-timing-function;
+      &.ng-hide {
+        background-color: white !important;
+        transition-duration: 0s;
+      }
+    }
+  }
+}
+
 @media (max-width: $layout-breakpoint-xs) {
   md-dialog {
     &[flex-xs="100"],