@Nordlicht
Thank you for the detail, it makes troubleshooting much easier even if I don't read German.
Anyhow the problem you've listed is a known issue. See the larger banner on the first post (
#1 link) for more details.
In short you must either revert back to version (
2.5.2)
or
Download ePublisher (
link)
@Student1
I suspect you are having the same problem as Nordlicht. Try either reverting back to 2.5.2 or downloading ePublisher.
=X=