If you have sync, and there is a problem anywhere, Shut Down Sync Immediately On All Devices to prevent the problem from spreading. Once the problem is fixed, perform the same repair on all computers/profiles before using sync again.

[v57+] Places Maintenance is built into Firefox.

Type about:support<enter> in the address bar.

You will find Places Database near the bottom. Press the Verify Integrity button.

If any errors are reported, check this link: https://support.mozilla.org/en-US/kb/fix-bookmarks-and-history-will-not-be-functional

The places.sqlite file contains your History and Bookmarks. And it looks like it is corrupted.

Type about:support<enter> in the address bar.

Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox.

Locate the above file. Then rename or delete it. Restart Firefox. The browser should then create a new place.sqlite and recover your bookmarks from the backup files.

Note: Your history is not backed up and will be lost.

Thank you for your prompt reply. I tried what you suggested but got no errors. This is what I found in the file: The places.sqlite database is sane Unfortunately, I have been trying to solve this problem for a few days and I have Sync turned on so the problem has probably propagated to my android device. I know that my Bookmarks entry on the taskbar is gone on both my android and my Windows computer.

Any other ideas? Thanks again.

I know that my Bookmarks entry on the taskbar is gone on both my android and my Windows computer.

On Windows, do you mean the top menu bar (File, Edit, View...) or the main toolbar with the page address on it?

There is an optional bookmarks menu button for the toolbar () you can add using the Customize panel (Customize Firefox controls, buttons and toolbars).

I am having two major problems with bookmarks. 1. I can't add an existing folder to the bookmark toolbar. I can add a bookmark, but not a folder. 2. I have added a couple of empty folders and cannot delete them. I have clicked on "remove folder" in multiple locations and nothing happens.

Do you use any bookmark-related add-ons?

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 a 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. Note that you may have to restore an older backup.

• https://support.mozilla.org/en-US/kb/restore-bookmarks-from-backup-or-move-them

See also:

• https://support.mozilla.org/en-US/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file
• https://support.mozilla.org/en-US/kb/fix-bookmarks-and-history-will-not-be-functional

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.

• 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