The title says it all. Once I try accessing youtube, firefox freezes and I have to force kill it with killall firefox or xkill firefox . The issue is youtube specific; other video websites , such as vimeo or dailymotion work. The following didn't help:

  • sudo apt-get purge firefox and reinstall
  • -safe-mode
  • Disabling HTML5 or flash

Ubuntu 14.04, Firefox 40.0.3

Update 1

In private mode, with renamed profile, or with .mozilla directory removed, firefox loads youtube alright. But as soon as I sign in to my account, it lags, which makes me resort to killall .

  • What kind of flash plug-in you use? Sep 19, 2015 at 13:45
  • Well, then the problem is in your user profile folder. There's a good chance it's an extension. Try to disable all extensions. If the problem goes away, it's an extension problem. Try re-enabling them one by one until the problem occurs again. But to be honest, I'd deal with a problematic profile folder by copying the important stuff (e.g. places.sqlite), deleting the folder and starting anew. I find it easier to re-install all extensions and make a few configurations than to spend twice the amount of time debugging, not to mention Firefox tends to get faster with a fresh profile folder. YMMV.
    – Yamaho
    Sep 19, 2015 at 17:11
  • @Yamaho I've done all that stuff over and over and over. Deleted .mozilla folder ? Check. Deleted .macromedia folder ? check. Even tried older versions of firefox. with .mozilla folder removed, as if it was all a new install. Nothing. Nill. Zip. Nada Sep 19, 2015 at 17:13
  • What does your latest Firefox health report say?
    – user364819
    Sep 19, 2015 at 19:09
  • After upgrade for Firefox came out, problem disappeared. Definitely was a bug. Oct 2, 2015 at 21:53

2 Answers 2


This might work: Reset Firefox Profile

Press the Refresh Firefox blue button.

  • Link says page not found. In any case i upgraded firefox and it's working fine now. Definitely was some bug Oct 2, 2015 at 21:52
  • the link, I had a typo. This is the correct link: link
    – mindtab
    Oct 29, 2015 at 2:47

The solution is adding www.youtube.com###guide-container to any adblocker (uBlock in my case) solved the freezing Problem and disabled the left side Menu. 👍👍

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