JIRA - Rich-Text-Editor not loaded in Admin-Configuration

Does somebody found any solution for that problem?
I had similar problem on Jira 7 and could solve it using information from this thread

But now for Jira 8 I have again this problem (on Jira 7 it works just fine), like it is mentioned in the topic. Seems that some dependency is not injected.
Any hint would be helpful.
Thanks