JS console error after create content step 2

• Use create content in the CM to create a new document.
• Fill in all fields for step 1
• Fill in fields you need for step 2
• When clicking the Save button this error shows up twice in the javascript console of the browser (Chrome in my case):

angular.js?21b1:14800 Error: [$compile:nonassign] Expression 'undefined' in attribute 'loading' used with directive 'contentEditor' is non-assignable!