Hi

Is this also happening on the other device you have connected to Firefox Sync?

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

If you use Sync then best is to reconnect one device at the time and wait for the initial Sync to finish before connecting another device when you are done fixing the bookmarks.

Yes, this is happening on my other devices connected to Sync. I have turned sync off but it doesn't seem to help.

I have previously gotten to the "Verify Integrity" step in troubleshooting as I've tried to solve this problem. I could not tell if I had errors from the text there. I consider myself relatively tech-savvy at a lay level but I could not tell from the language there if I had errors, so I stopped there.

Now, when I tried to do this again, Firefox restarted and the menus have all disappeared so I can't even get to the verify integrity location.

After restarting my computer, I was able to run the "verify database" again. This time, the feedback is that both folders you mention are "sane."

The next suggestion is: "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"

Where would I do this renaming? I am not familiar with a Firefox profile folder so am unsure how to do this.

Thanks for your help.

You can find a button to go to the profile folder further up on the about:support page like I posted above at the end of my reply.

• 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 have deleted the places.sqlite and favicons.sqlite files as directed and reopened Firefox. Within minutes I have over 1000 duplicate bookmarks again. I am open to further suggestions.