Each of those files is a backup of all your bookmarks. If they are all dated 2022, that means you have altered your bookmarks 15 times or more this year. Try restoring the latest.

How do I restore them?? I click on the up/down button in 'manage bookmarks' (restore) and they do show up as a list but every time I try to chose one of the files I get the message "unable to process the backup file'!

If you use Sync then best is to disconnect Sync temporarily during troubleshooting.

This could be a problem with the places.sqlite and favicons.sqlite files in the Firefox profile folder.

• use the "Places Database" -> "Verify Integrity" button on the "Help -> More Troubleshooting Information" (about:support) page

If errors are reported with "Verify Integrity", close and restart Firefox or reboot and retry.

If "Verify Integrity" cannot repair places.sqlite, rename/remove all places.sqlite and favicons.sqlite files in the Firefox profile folder with Firefox closed. Firefox will rebuild places.sqlite and restore the bookmarks from the most recent JSON backup in the bookmarkbackups folder.

• keep a backup copy of places.sqlite in case a new places.sqlite database has to be created
• you lose the history when a new places.sqlite is created

You may have to restore an older bookmarks backup in the bookmarkbackups folder via the Bookmarks Manager (Library).

• Bookmarks -> Show All Bookmarks -> Import & Backup -> Restore
• https://support.mozilla.org/en-US/kb/restore-bookmarks-from-backup-or-move-them

See also:

• https://support.mozilla.org/en-US/kb/fix-bookmarks-and-history-will-not-be-functional
• https://support.mozilla.org/en-US/kb/cant-add-change-or-save-bookmarks

You can use the button on the "Help -> More Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page (Root directory).

• Help -> More Troubleshooting Information -> Profile Folder/Directory:
  Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data

I don't use Sync at all.

This is what I get when I click "Places Database" -> "Verify Integrity" button on the "Help -> More Troubleshooting Information" - "Verify Integrity": > Task: checkIntegrity - Unable to fix corruption, places.sqlite will be replaced on next startup > Task: invalidateCaches - The task queue was cleared by an error in another task. > Task: checkCoherence - The task queue was cleared by an error in another task. > Task: expire - The task queue was cleared by an error in another task. > Task: originFrecencyStats - The task queue was cleared by an error in another task. > Task: vacuum - The task queue was cleared by an error in another task. > Task: stats - The task queue was cleared by an error in another task. > Task: _refreshUI - The task queue was cleared by an error in another task.

I tried rebooting (again) and still nothing.... I will try renaming files as you said and post my progress. It should not be this hard to keep my bookmarks, this is very frustrating!

Ok, I removed 'places' and rebooted computer and low and behold the bookmarks returned! I have no idea why it happened in the first place and I have even less understanding of how I got them back. I lost my toolbar apps, but I can live with that. Thank you for your help cor-el. I must admit, I'm not a big fan of Firefox anymore after this, it really shouldn't be so hard to get lost bookmarks back. But thanks for your help.