Please backup the Firefox profile on Each of the PCs. The profile location on the PC may be found whilst Firefox is open by using a Button on the troubleshooting page. Put the backup profile somewhere safe, outside Firefox profile of program paths. Your My Documents would be a suitable place. For full instruction see

• Back up and restore information in Firefox profiles

The profile has important bookmarks files, a database and some automatic backups, that we will need later.

For now try the following steps only on the PC you are using to post to this forum We will need to sort out the others later Turn off the option in Firefox Sync that lets you Sync Bookmarks

• How do I choose what information to sync on Firefox?

Does Firefox work ok now once you restart it with the Sync option changed ?

If it does not and appears to have a similar bookmarks issue then:

1. With Firefox open find the file in your profile called places.sqlite
2. Close Firefox
3. Rename the file places.sqlite.old-01
4. Restart Firefox.

Firefox will recreate a places.sqlite database and may start up ok. At this point you will have lost all your History. The bookmarks listing may have improved, it depends on when the problem occurred and which backup file Firefox tries to use. We should be able to get the history back. We may be able to get back some or even most of the bookmarks.

Post back to say how you got on, and to confirm you made the backups of the profiles.

We will see what else can be done once I know you have made backups.

See also

• Recover important data from an old profile
• Restore bookmarks from backup or move them to another computer

Personally I would advise if anyone and everybody that uses Sync on Bookmarks to always ensure you keep regular manual backups of bookmarks. I tend not to use sync these days. I have learnt its ability to mess up bookmarks makes it more trouble than it is worth.

Thank you. After changing the file name places.sqlite everything works fine(old files on both PC's saved). Now how can I recover needed bookmarks?

Firefox would normally restore the bookmarks automatically from the most recent JSON backup in the bookmarkbackups folder if you delete files (make sure to remove places.sqlite-shm and places.sqlite-wal as well). If that didn't work then you can restore the bookmarks manually in the Bookmarks Manager (Library).

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

See also:

• http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox
• https://support.mozilla.org/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file

• Places Maintenance: https://addons.mozilla.org/firefox/addon/places-maintenance/

If you use Sync then best is to disconnect Sync (temporarily) while performing maintenance/repair efforts to the places.sqlite database.

A few more comments.

Make sure you leave sync off certainly for syncing of bookmarks as we have both mentioned.

When you try to restore bookmarks using the bookmarks manager (Option all bookmarks '- Shortcut is Ctrl + Shift + B on Windows) you will not that you are shown the date,size and number of bookmarks.

I am hoping that if this is a recent and sudden issue you will be able to easily find an uncorupted backup set, because of a jump in the numbers. You can experiment a bit here an try different ones, making note of which one is the best. Remember at this stage we are using a new places.sqlite that has no history content. (I do not know how important History is to you. The location bar utilises it some people find the majority of their sites from the History - even if they do not realise it themselves! )

• Please try that and say how you get on. Did you find a good set of bookmarks, with no duplicates ?
  • Did you manage to restore them ?

I asked you to backup the profile on each PC Can you please confirm that you did that, or explain what happened and any problems you had ?

And something that may or may not be be related to this problem

• Do you, or have you recently used Google Chrome on any of these devices ?
  • Did you ever import or try to import Bookmark from Google Chrome
  • Did that workout ok ? Roughly how long ago was it that you tried that if you remember ?