Hi Peter,

I understand that you recently updated Firefox on your Mac and encountered some issues where all your bookmarks, history, and passwords seem to be missing. I'm here to help you recover your data.

First, please try the following steps:

Go to the Firefox menu and select "Preferences" or "Options" (depending on your version). In the Preferences/Options menu, navigate to the "Sync" tab. Check if you have previously enabled Firefox Sync. If you have, sign in to your Firefox account using your username and password. This should sync your data, including bookmarks and passwords, back to your browser. If you didn't enable Firefox Sync or it doesn't retrieve your data, we can try a few other methods:

Check the Firefox profile folder on your Mac. To access it, follow these steps:

Open Finder. Click on the "Go" menu in the top menu bar. Press and hold the "Option" key on your keyboard. You should see the "Library" option appear in the Go menu. Click on it. In the Library folder, open the "Application Support" folder, then the "Firefox" folder. Look for a folder named "Profiles." Inside this folder, you should see a folder with a random string of characters followed by ".default." Open this folder. Check for files with names like "places.sqlite" and "key4.db." These contain your bookmarks and passwords, respectively. If you find the above files in the profile folder, we can try to restore them:

Close Firefox completely. Make a backup of the existing files (places.sqlite and key4.db) by copying them to a safe location on your computer. Rename the files you found earlier to "places.sqlite" and "key4.db" respectively. Start Firefox and see if your bookmarks and passwords are restored. If these steps do not resolve the issue, or if you need further assistance, please let me know. I'm here to help you get your data back.

Best regards, Firefox Support Volunteer

IMPORTANT: key4.db by itself does not contain any saved logins. It is part of a lock-and-key file pair and you will also need its companion logins.json file if you are using files to copy data from a backup. For more complete details on what various files store, see: Recovering important data from an old profile / Back up and restore information in Firefox profiles.

But first:

If you haven't already, quit out of Firefox and do a normal shutdown and restart of your Mac to complete any pending updates and release any file locks.

If Firefox again starts up without your data, could you check whether your stuff is available in a different profile, as follows:

Profile Manager Page

Inside Firefox, type or paste about:profiles in the address bar and press Enter/Return to load it.

This page should list at least one profile and could list many. (Each profile has two folders and one or more buttons. Do not use any Remove buttons!)

The profile that Firefox is currently using will have this:

This is the profile in use and it cannot be deleted.

Do you have any other profile(s) listed on this page? If so, you can check whether it is the one you were using recently by clicking its Launch profile in new browser button.

If it isn't what you want, simply close that new window.

If it IS what you want, back on the about:profiles page, click the Set as default profile button for that profile so Firefox uses it automatically at the next startup.

Any luck with this method?

Thanks suram080!

I've just started a Firefox account, so I won't be able to sync what was on this computer.

I've found the file "places.sqlite" and "key4.db." and copied them to my desktop. I'm not sure what you mean when you say 'Rename the files you found earlier to "places.sqlite" and "key4.db" respectively'

Also, there is a "places.sqlite.corrupt" file in that user folder. Not sure if that is important.

When I do reload Firefox after following your suggested steps, I get the message that 'Bookmarks and history system will not be functional because one of Firefox's files is in use by another application. Some security software cause this problem'.

Thank Peter

The places.sqlite database file stores bookmarks and history and the presence of a places.sqlite.corrupt file and the error message about Bookmarks and history system... indicates a problem with this file.

If you use Sync, 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 -> Manage 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