Firefox constantly hangs (even in safe mode), and uses 50% CPU while doing so
I use Firefox 36.0.1 and Windows XP (32-bit version).
Lately, Firefox has been doing this weird thing where it randomly stops loading anything, as if the connection was lost (it isn't, everything else works just fine). When this happens, Firefox uses 50% CPU, when it usually gravitates around, well, 0%. Restarting the browser, or waiting for a few minutes "fixes" the problem temporarily. Same thing happens in safe mode, too.
I have a feeling this *might* be linked to Flash, since it seems to happen much more often when I'm trying to watch videos, or streams on Twitch. I've tried disabling plugin-container, and updating the Adobe Flash Player plugin, with little success. Malwarebytes couldn't find anything, either, and it doesn't feel like a virus anyway.
Whatever the case, I'm out of options at this point. I've been having quite a lot of problems with Firefox for a while now, especially when it comes to videos/animations (I can't play most Vine.co videos, for instance), and it's starting to make it difficult for me. I really don't want to switch to Chrome, I don't trust Google, and their browser lacks many key features I enjoy in Firefox (such as the bookmarks sidebar <3), so I really hope I can get some help here.
Any suggestions?
Chosen solution
With Chrome being a pain, I tried to go back and fix Firefox again, and (so far) I think I've found the problem. I have to mention that I did try those 5 suggestions before, btw, and none of them got rid of the problem. Yes, even in safe mode, with a blank profile, no plugins, no firewall, and no tabs, it still happened, somehow. And yes, Chrome would work fine with Firefox running in the background, just like I mentioned in my previous post.
What did it for me was disabling both Prefetching and IPv6 in about:config, following the instructions on this this page .
I'm not sure which one did the trick (I'm a bit scared to mess with that again, but I could test it out if you want, it could be useful to others), but it looks like everything is fine for now.
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See if this helps;
Flash block {web link} Never be annoyed by a Flash animation again! Blocks Flash so it won't get in your way, but if you want to see it, just click on it
https://support.mozilla.org/en-US/kb/firefox-slow-how-make-it-faster
https://support.mozilla.org/en-US/kb/firefox-uses-too-many-cpu-resources-how-fix
https://support.mozilla.org/en-US/kb/firefox-hangs-or-not-responding
I didn't bother to reply last time, but yeah, I already knew about Flashblock, already had it installed, and no, obviously that's not the problem. Sometimes Firefox will do that before I even try to load any website, anyway.
I tried refreshing the browser, I uninstalled, deleted my profile, deleted anything Firefox related on my computer, installed it again, and it still does it, constantly. I ended up switching to Chrome, I couldn't find a fix, I can't even begin to understand why this happens. I'm not exactly happy with Chrome either, it's full of problems as well, and I don't like it, which is why I used to have Firefox, but... At least it works.
So if you have this problem, if you've tried what I've tried, and it still happens, I guess just switch browsers, there doesn't seem to be an alternative, sadly.
If this only happens when you have FlashPlayer installed and active then it probably is related to FlashPlayer.
There are steps that may be taken to find what cause this. But the steps are not easy.
If the problem is FlashPlayer related see
It's not Flash, I don't think. I thought it was at some point, but it's definitely not. I just reinstalled Firefox quickly to give it a try, and it hanged immediately, before I even had time to open any tab, or... do anything. All of my plugins are up to date anyway, I don't think they're the problem.
It's something with Firefox itself. As I'm typing this with Firefox in the background, it did that four times already. Went all the way up to 50% CPU, then back to 1-2%. No reason at all, I'm not even using it, it's just running in the background without any tabs. That's why I don't get it, I can't even pinpoint the problem. It just started one day, and the "freezes", if you can call them that, kept getting more and more frequent. I can't use it anymore, it happens all the time.
I feel like I've tried everything, it's like Firefox just doesn't want anything to do with my PC anymore. I know it's starting to show its age, but there's no reason it shouldn't work on paper. I don't know, did Firefox suddenly stop supporting Windows XP?
What you describe is obviously a severe probem, but you need to know not everyone sees this. It is most likely a problem with your specific setup or installation not a general Firefox problem.
Firefox is not going to support XP with the new 64 bit browser, but otherwise continues to support XP. I still have an XP that I tried that with Firefox a few weeks ago and the XP still worked with Firefox.
I know you will have had a go at some of this but can you go through in an orderly manner and test out and report your results as follows.
- Try Firefox with all plugins disabled and in its Safe Mode.
Do you still see the problem then ? - Try a new additional Firefox profile, as a test, and again in Safe Mode and with all plugins disabled.
- I am sure if your only tabs are the new tabs or blank pages you get no issue, can you confirm that please ?
- Did you read Firefox hangs or is not responding - How to fix? Can you pin down when this problem occurs at all ? Do you get any error messages ?
- Temporarily disable all security related software, including the firewall. Does that solve the issue ?
If you test with only tabs open from our support.mozilla site you will minimise any security risk
Are you able to run two browsers at once ? Is internet Explorer or Chrome working ok while you have these problems in Firefox ?
Chosen Solution
With Chrome being a pain, I tried to go back and fix Firefox again, and (so far) I think I've found the problem. I have to mention that I did try those 5 suggestions before, btw, and none of them got rid of the problem. Yes, even in safe mode, with a blank profile, no plugins, no firewall, and no tabs, it still happened, somehow. And yes, Chrome would work fine with Firefox running in the background, just like I mentioned in my previous post.
What did it for me was disabling both Prefetching and IPv6 in about:config, following the instructions on this this page .
I'm not sure which one did the trick (I'm a bit scared to mess with that again, but I could test it out if you want, it could be useful to others), but it looks like everything is fine for now.
You have found a solution, so that is good. Thanks for posting back to explain what worked for you.
You apparently followed instructions from
I'm not sure which one did the trick (I'm a bit scared to mess with that again, but I could test it out if you want, it could be useful to others), but it looks like everything is fine for now.
There are some risks with trying new profiles, and messing with about:config so if it works for you like this it is probably best leaving it as it is.