Please : https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer and https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles then https://support.mozilla.org/en-US/kb/refresh-firefox-reset-add-ons-and-settings TEST....... If no issues then Extensions which need to be added back in 1 at a time and tested ..... Or it is your Profile : Make a new one and test ...: https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

Please let us know if this solved your issue or if need further assistance.

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

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

None of these suggestions worked for me.

uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files and C:\Program Files(x86) Then restart system. Then run Windows Disk Cleanup. Then run it again and click the button that says Cleanup System Files. Note: your Firefox Profile is saved. But you should make a back up before you do : https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Reinstall with Current Release Firefox 57.0.1 with a Full Version Installer https://www.mozilla.org/firefox/all/

Please let us know if this solved your issue or if need further assistance.

Do you see any errors in the Browser Console related to Places (bookmarks and history)?

• "3-bar" menu button or Tools -> Web Developer
• https://developer.mozilla.org/en/Tools/Browser_Console

Errors are showing in the Browser Console, but I don't see anything obviously related to bookmarks or history. However, I'm not a Tech. If I can't come up with another solution, I will probably try uninstalling and reinstalling Firefox--as suggested above--and see if that makes a difference.

I uninstalled and re-installed Firefox and ran disk cleanup, per instructions above. It still will not bookmark. I have used Firefox forever, but I bookmark frequently, and Firefox is useless to me without it. I have no choice but to give up on it and use another browser. Very disappointed.

You can create a new profile to test if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

I opened with a new profile, and the bookmark feature seems to be working now. I lost all of my old bookmarks, however, along with other customized settings. I'll work on trying to get those back. It seems very odd to have to go through all this just to accommodate a new Firefox update, but thanks for the help!