Ticket #6315: 6315.patch

_source/plugins/div/dialogs/div.js

@@ -508 +508 @@
                         },
                         onHide : function()
                         {
-                                this._element.removeCustomData( 'elementStyle' );
+                                // Remove custom style only when editing existing DIV. (#6108)
+                                this._element && this._element.removeCustomData( 'elementStyle' );
                                 delete this._element;
                         }
                 };