Update to Drupal 8.1.0. For more information, see https://www.drupal.org/drupal-8.1.0-release-notes

core/modules/quickedit/js/models/BaseModel.js

@@ -3,7 +3,7 @@
  * A Backbone Model subclass that enforces validation when calling set().
  */
 
-(function (Backbone) {
+(function (Drupal, Backbone) {
 
   'use strict';
 
@@ -57,4 +57,4 @@
 
   });
 
-}(Backbone));
+}(Drupal, Backbone));