Hi raph871, have you noticed anything like the message described in the following article:

Fix "The bookmarks and history system will not be functional" error message

Could you test in Firefox's Safe Mode? In its Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the option/alt key when starting Firefox. (On Windows, hold down the Shift key instead of the option/alt key.)

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" Help button > Restart with Add-ons Disabled
• (menu bar) Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

Sadly I have tried using safe mode and it has not helped. Also my bookmark system isn't working, I can't bookmark anything or change my bookmarks but my history is fine.

Hmm, it's troubling that bookmarks are just not working.

The Troubleshooting Information page has a "Verify Integrity" button to do a little light maintenance on the Places database (where bookmarks and history are stored). You can open that using either

• "3-bar" menu button > "?" Help > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

Then scroll way down or use Find to search for Integrity in the Places Database section. At first, nothing will seem to happen, but then several seconds after clicking the button Firefox should report some diagnostic results below it.

Please copy/paste the results somewhere safe, then quit/restart Firefox to see whether it helped.

The Verify Integrity button has not done anything for me yet, I pressed it as soon as I received the email that you replied and still nothing has happened.

Have you shut down and restarted your Mac since this problem began? I wonder if there is a random file lock or privileges issue. Maybe that only happens on Windows...

Yes I have done this countless times, also reinstalled firefox, refreshed all preferences, etc but nothing has changed. This problem has been going on for about a month now and it has only been ever since I downloaded MacOS Mojave so maybe Firefox is not optimized for this update yet as it is only a beta, but I still would love to figure out how to stop it because for my school work there are many websites I have to go to that aren't very accessible just from searching a term and also I can't bookmark them.

You might need to dump the Places database and have Firefox generate a new one. This will remove all history and bookmarks, and Firefox should automatically restore the last automatic bookmark backup. Since it's not 100% reliable, you should keep a copy of the database in case you need to revert to it.

Make a Bookmark Backup

Firefox has two formats and I recommend creating both:

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

Remove the Places database

This is the file that stores history and bookmarks. Open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" Help > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter/Return

In the first table on the page, on the Profile Folder row, click the "Show in Finder" button. This should launch a new window listing various files and folders in Finder. (If Finder shows a folder with a name like a1b2c3d4.default selected, double-click into that folder.)

Leaving that window open, switch back to Firefox and Quit, either:

• "3-bar" menu button > Quit
• (menu bar) Firefox > Quit Firefox

Pause while Firefox finishes its cleanup, then rename places.sqlite to something like placesOLD.sqlite. If you see files named places.sqlite-shm and/or places.sqlite-wal, you can delete those.

When you start Firefox back up again, it should attempt to rebuild your bookmarks from the latest automatic backup. If that doesn't work, you can restore/import from one of the backups you made in the first step (only one needs to work):

• "Restore" the JSON file: Restore bookmarks from backup or move them to another computer
• "Import" the HTML file: Import Bookmarks from an HTML file

Any improvement?

Thanks I can now bookmark things which is great but for some reason the search still won't suggest any websites.

Well, we did just erase history... Does Firefox suggest any of your bookmarked sites? If not, could you double-check these preferences (they correspond to various checkboxes on the Options page):

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful or accepting the risk.

(2) In the search box above the list, type or paste URLB and pause while the list is filtered

(3) These preferences have a default value of true, if they are bolded and "modified" to false, you can double-click them to restore them to true as desired:

• browser.urlbar.suggest.bookmark
• browser.urlbar.suggest.history
• browser.urlbar.suggest.openpage ("switch to tab")
• browser.urlbar.suggest.searches (search engine suggestions)

The following preference is sort of a master switch, but changing it tends to modify the others and vice versa. I'm not quite sure how it works, but it should be set to true:

• browser.urlbar.autocomplete.enabled

Was there anything unexpected there?