Hi Jelvis69, I suggest making a couple backups for safety. Firefox supports two different formats, and it's best to create both:

• JSON "backup" format: Restore bookmarks from backup or move them to another computer
• HTML "export" format: Export Firefox bookmarks to an HTML file to back up or transfer bookmarks

Then you could try a "Refresh." That will remove your add-ons and customizations, so if you want to try less drastic things first, let us know: Refresh Firefox - reset add-ons and settings.

Have you tried right clicking on a space in the menu bar. Are Menu Bar and Bookmarks Bar both checked?

Did you try to click the Restore Defaults button?

Is both the Bookmarks Toolbar visible and do you see the "Bookmarks Toolbar Items" on this toolbar or elsewhere in the palette?

Do you see the content of the Bookmarks Toolbar folder in the sidebar and in the Bookmarks Manager (Library)?

You can check for problems with the places.sqlite database (bookmarks and history) in the Firefox profile folder.

• use "Verify Integrity" on the "Help -> Troubleshooting Information" (about:support) page
  close and restart Firefox in case errors are reported and retry

See also:

• http://kb.mozillazine.org/Locked_or_damaged_places.sqlite
• https://support.mozilla.org/en-US/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file

Feedback? Have we helped?

Jelvis69 - An answer - positive or negative - can help many other users.