sorry for the late response - I was on a business trip.
I Filtered by ERROR in Web Console and received the following (please note, that xxx.com is just a replacement for the actual and existing domain!):
10:16:11.700 [Mitteilungsdetails anzeigen/ausblenden] TypeError: c.get(...) is undefined[Weitere Informationen] jquery.min.js line 2 > eval:463:20
http://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.min.js line 2 > eval:463:20
Does this help?! Alternatively I may be stupid to use the console....
If it helps you, I can also give you the login details for the webpage with a seperate user and you can check out the issue by yourself?
Thanks and cheers.