Ran TFF once, now getting JS errors in FF and Safari and constant quits

Lon McQuillin's Avatar

Lon McQuillin

17 Jun, 2014 06:17 PM

I ran TFF once before noticing that it doesn't support Flash, so I switched back to Firefox and Safari. I now get constant JavaScript error messages, and both FF and Safari are constantly quitting unexpectedly.

How can I undo the damage caused by running TFF that one time?


  1. Support Staff 1 Posted by Chris (chtrusch... on 17 Jun, 2014 06:58 PM

    Chris (chtrusch)'s Avatar

    Hello Lon, TenFourFox uses the same user profile as Firefox 3.6, and since it's a much more recent application, it will have updated the user profile, maybe in a way that old Firefox can't use it properly anymore.

    You can restore the profile from a backup, or just delete it; Firefox will create a clean new profile when it's started the next time. If you need you bookmarks, you can export them to html and then re-import them to the new profile. Your profile is at Macintosh HD>Users>(your user name)>Library>Applications Support>Firefox

    Safari is unaffected; if you see problems there, TenFourFox is not responsible.

  2. 2 Posted by Lon McQuillin on 17 Jun, 2014 07:47 PM

    Lon McQuillin's Avatar


    Thanks for the very quick reply!

    I looked into the Firefox/Profiles folder, and there's a ton of stuff
    in there that appears to be important. Which file(s) should I be
    looking to delete to reset?



  3. Support Staff 3 Posted by Chris (chtrusch... on 17 Jun, 2014 08:04 PM

    Chris (chtrusch)'s Avatar

    Actually, the whole "Firefox" folder. Try the following: Quit the Firefox browser, then move the complete "Firefox" folder out of Application support and to the desktop. Re-start Firefox and see if you're missing something. If not, you can trash the "Firefox" folder containing your old profile.

Reply to this discussion

Internal reply

Formatting help / Preview (switch to plain text) No formatting (switch to Markdown)

Attaching KB article:


Attached Files

You can attach files up to 10MB

If you don't have an account yet, we need to confirm you're human and not a machine trying to post spam.

Keyboard shortcuts


? Show this help
ESC Blurs the current field

Comment Form

r Focus the comment reply box
^ + ↩ Submit the comment

You can use Command ⌘ instead of Control ^ on Mac