All previously LibreOffice files corrupted

Using LO on a Mac silicon (M2) and LO 25.2.3, I try to open documents saved end of last year. I have for ALL files the same error: Document corrupted, try to repair → no repair possible.

Same for ods, odt files. New files can be saved.

If I make a new file and try to open an old file now, the text conversion dialogue opens. But the resulting file is empty.

Any help here?
Best
Markus

can you upload a screenshot here.

what happens if you copy your_file.odt to your_file.zip,
then try to open it with Finder ?