I've found a page that isn't rendered correctly by Firefox with my usual profile. It is rendered correctly with a blank profile.

I have quite a few add-ons. One of them is surely the culprit. How can I find out which?

Userscripts often affect the rendering. But I turned off Greasemonkey, and it didn't help. So it's something else, presumably an extension (what else could it be? I have no chrome/userChrome.css.). I'm looking for an easy way to find out which one, easier than disabling a bunch of extensions and restarting umpteen times.

Related: Create a tool to help users identify a problematic add-on by bisecting the list of installed add-ons — a similar problem which would admit a similar solution. I want to automate this as much as possible; something like git bisect, that doesn't require me to change my actual profile, would be ideal. A Linux-specific solution is fine with me.

  • Ad Blocker? I'd imagine most of your addons don't affect rendering that much besides that – cloneman Oct 8 '12 at 22:36
  • @cloneman Thanks for the suggestion, but I don't use Adblock. Greasemonkey and Flashblock are the only two addons which look like they should affect the rendering. Clicking “disabled” in the Greasemonkey menu and opening the page in a new tab didn't help. I haven't tried disabling Flashblock but the page has no flash so I have little hope. – Gilles 'SO- stop being evil' Oct 8 '12 at 22:42
  • 1
    It is a PITA in firefox, which requires a restart to enable/disable. I usually disable everything, and then re-enable one at time. Hopefully some can suggest something a lot better. – Zoredache Oct 9 '12 at 2:16
  • Backup your profile to prevent any unwanted changes. Disable half of extensions, check for the issue. If issue is present, the other half of add-ons is where the fault lies. This will automatically half the number of add-ons you have to check. Repeat until you have isolated the problem. Now restore your profile from the backup (copy+paste should work) and remove/disable/fix the problematic add-on. You should not have enough add-ons for this to be an unfeasible solution. If you do, I would suggest getting rid of a few for performance/memory related improvements. – Wk_of_Angmar Oct 9 '12 at 17:01

AdBlock or NoScript or FlashBlock would be obvious suspects. Or any other extension which touches the client area (like SearchWP).

If you back up your profile directory (this gets all your sqlite files and extensions and preferences) and then remove your sessionstore.js file, then restarting Firefox a bunch of times might not seem so painful.

Disable all your extensions (and plugins), and if problem is fixed, then re-enable several at a time until the problem resurfaces. If it's not extensions, then go after other things like any customizations in about:config (prefs.js), etc.

Also, I've experienced weird problems which weren't caused by extensions at all. The cookie option "Always Ask" once broke Facebook for me, for no reason I could figure. I simply had to permit cookies for that profile.

Restoring your profile directory would undo anything you did while testing (including erasing any history). Profile directory on Windows is at %APPDATA%\mozilla\firefox\profiles\SOMENAME . I don't remember where it is in Linux, but I'd guess $HOME/.firefox/profiles/SOMENAME (or something like that).

  • Another place to find the "suspect" is in about:support in Important Modified Preferences... – climenole Oct 9 '12 at 2:37

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.