I GOT IT.
When i uploaded the english language files in my folder "language/german/" I took them from the downloaded zip file from your Server.
But while processing the update the script changed something with these files.
So the solution is:
1) make a backup of the folder "language/your_language"
2) delete al the content on your webserver in the folder "language/your_language"
3) download al the content of the folder "language/english"
4) Upload these folders / files to your webserver in the folder "language/your_language
Now everything should work ... at least in english.
This is a major Bug because all non englisch UBB boards will run into this problem.
.... is now retranslating the files ;-)
