Thank you very much for your question and the associated hint!

I tried it, but the problem still remains.

When I want to add/edit my Bibliography I always have to delete the old Bibliography first before I can really get into the window "Literaturverzeichnis editieren" (in German :)).

Otherwise
1. the bibliography will either be inserted again after the "old" one or
2. following the point where the cursor was when I clicked "Add/Edit Bibliography" or
3. only the part after the point where the cursor was when I clicked "Add/Edit Bibliography" will be inserted again.

Tricky case, but hopefully not unsolvable...

Thank you for your time and brainpower!

Thanks very much for your hint again!

I read through the informations in the corresponding link.
In my document the already inserted citations are already highlighted in gray without clicking them. Clicking Add/Edit Citation the citation dialog appears with the corresponding citation. So the citations seem to be active fields.

Do the entries in the bibliography have to be active fields as well? I am wondering if my bibliography is flattened (with active citations) as there are no corresponding information when I click on parts of the bibliography. If it is flattened, the recommended new insert of the bibliography by clicking Add/Edit Bibliography doesn´t help me out.

Thanks for your ongoing support!

After a Zotero free weekend (:)) I am sending my "Thanks you´s!" in your direction!

Will the Zotero Dev will get back to me or do I have to actively reach out?

Have a lovely rest of the day!

@adomasven would have to take a look, but @feffi2013, make sure you're running the latest version of Zotero and a current version of LibreOffice. We'd also want to see a Report ID.

But you should test whether you can reproduce this in a new, empty document. If not, see Troubleshooting Errors in Word Processor Documents, in particular the last step.

See the last point here: https://www.zotero.org/support/kb/moving_documents_between_word_processors