My bookmarks disappeared and I'm unable to get them back or add them back manually.

tfischer1, it might be worth checking the integrity of your Places Database files, which are where Firefox stores bookmarks and their icons. To do this: # Go to Help menu (press alt+H). # Select "More Troubleshooting Information". # On the page that opens, scroll down to "Places Database" and press the "Verify Integrity" button. # Once the check has finished, Look for any lines in the report that startt with a "-" or that contain the term "error". If any errors are reported, try restarting Firefox and re-running the integrity check to see if they were fixed by the first check. You may want to repeat this 'restart and re-check' process again if errors are still found. ---- If that doesn't help, then you could try the steps in this article to see if your bookmarks can be found in a different profile: https://support.mozilla.org/en-US/kb/recover-user-data-missing-after-firefox-update