If you search here you will see quite a few of such issues, with possible reasons and solutions, so please search. If some of the things you try don't work get back here.

So I did before issueing my experience. Sadly none of those I found helped.

Meanwhile I tried finding a solution in a older back up on my disk. All the bookmarks were rather old.

Now I went via my passwords from Apple, via Safari and creted a new cvs-file. That helped only for those which were saved in my iOs from my phone. The bookmarkslist though is gone. When in the future I find a password gone at a specific site which wasn't in the Apple-list, I'll simply will renew it. As for now I'll make sure I'll reguraly save a cvs-file on my hd, not having to encounter such a stupid update failure. And of course I have disabled the automatic updates from Firefox, preventing to go wrong again from fully automated protocols.

Thanks for the update.

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