I had the same difficulty. When I opened the notebook (Windows 10 Version 22H2 für x64-basierte Systeme (KB5058379)), the system was just installing an update. After that, the error messagecappeared. Since I had not installed any app, program, or the like, the reason for the error could only be in Windows. I deleted the very last update, what was not completed, but apparently this has worked: After restart the notebook Firefox bookmarks appeared. What I don't know, however, is whether I achieved this success, or whether WIN or Mozilla had corrected whatever was necessary, in the meantime.