i would guess memory issue. try using the portableapps version of firefox 32 bit and 64 bit, copy your profile over to each of these and see if there is a change.

Neyo, Thank you for your reply. Firefox Quantum 64bit is currently installed on my machine MBA early 2014 4GBRAM

Could you please explain what you mean when you say: "using the portableapps version of firefox 32 bit and 64 bit, copy your profile over to each of these and see if there is a change."

Thank you.

go to portableapps.com get firefox portable and set it up, do not run it yet. go to your firefox profile folder https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data and copy it over to the portable profile folder (...\FirefoxPortable\Data\profile). now run firefoxportable and see if the problem persists.

you could also try the solution described here: https://support.mozilla.org/en-US/kb/how-to-fix-preferences-wont-save

Hi mistertdba, do you display the "Tags" column in the Library window ("Show All Bookmarks"), so you can confirm that your previously added tags are still there?

I'm not sure why the lists do not populate, that's troubling.

Could you test in Firefox's Safe Mode? In 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.

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

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

jscher2000 said

Any improvement?

I can confirm that Safe Mode in FF 58.0.2 (64-Bit) fixes the issue. Both the previous tags dropdown and the auto complete work again.

How do we find the culprit?

Actually, after restarting again without safe mode, the previous tags dropdown and the auto complete also work again.

A normal restart didn't fix the issue ( I tried many times), but it seems that entering and leaving Safe Mode does…

I'm using Firefox 57.0.1 on Ubuntu. I'm running it on safe-mode and I still can't add tags, see the dropdown, or autocomplete.

Hi ekoka, can you update to (or a least test in) Firefox 58.0.2?

Hi jscher2000. I did update to 58.0.2 and still had the same problem even in safe-mode.

This page however https://superuser.com/questions/111998/how-do-i-repair-a-corrupted-firefox-places-sqlite-database proved useful.

Thank you all for your input and apologies for late reply. I have found out that deleting the user and creating a new one works too.