A possible cause is security software (firewall,anti-virus) that blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.

Remove all rules for Firefox and the plugin-container from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox and the plugin-container process and the updater process.

See:

• https://support.mozilla.org/kb/Server+not+found
• https://support.mozilla.org/kb/Firewalls

I don't think it's this, because everything can be working for a while and then - bam.

It's just so random, and I can't even post a crash report because Firefox doesn't think it's crashed (there's no history in about:crashes). It just locks up solid and needs killing from task manager.

Since posting the original fault, I've removed Firefox and re-installed 14.0.1 - just in case - but no difference.

I experience the same problem. It all started yesterday afternoon. All of a sudden FireFox crashes or hangs.

14.0.1 is quite unstable but still workable for me. Just have to avoid any flash videos. pkhodgson, no need to go back to 13, v14.0 was fine!

YouTube scripts randomly crash, and honesty I'm tired of this. 1 bad update after another to try and compete with Google Chrome. Firefox used to be a unique experience but now it's ruined, Firefox is now just a cheaper version of Chrome. it's only advantage it has tab history. Plus this thing drains my cpu.

This is a total fail. My cpu is racing like crazy and it just crashed not only FF but my whole computer, which is unacceptable. Where is page to go back to previous version?

Sometimes the crash occurs even when I just switch between tabs.

There seems to be a problem with Firefox 14.0.1 and Bitdefender. On the Bitdefender forum someone tested after uninstalling Bitdefender and the crashes didn't occur anymore.

Anyone has this problem that doesn't have Bitdefender installed?

And I don't mean the Flash issue.

I started having problems tonight with firefox hanging or freezing up every few seconds - constantly, can't do anything. I was running the firefox beta and have been for a year or more with no major issues as far as firefox freezing up. So after it started freezing up every few seconds tonight I downloaded the Aurora version and it seemed to be working fine. But I decided to go back down to the regular version 14.0.1 because I'm kinda scared to take a chance with Aurora and the possible bugs that may not be worked out yet. Well I'm having problems with 14.0.1 freezing too. I may have to go back to the Aurora. I wish firefox could get this straightened out. It seems like it is constant problems lately with firefox not working correctly with youtube, realplayer and adobe. I have no problems with chrome. I have prefered firefox over chrome up until recently and if the problems persist I may just start using chrome.

The en-US version is infected with a trojan: TROJ_GEN.F47V0719. Scanned it using virustotal.com.

https://www.virustotal.com/file/e682be3ba4e97c8ecc266e7d17bc69d74d8698467be992c9b0c26287e619af3c/analysis/

Only 1 of 42 makes the claim and as a result could easily be a false-positive which is not uncommon after a new Firefox release and new definition update for antivirus.

I upgraded to Firefox 15 (beta) and the problems seem to be solved. You can find this version here

The problem started for me with the beta 15. The aurora seemed to work fine but I didn't want to take a chance with aurora and the possibility of bugs with it. So I downgraded to the 14.0 which is working okay. I have had it to freeze up a couple of times but nothing like the beta 15 was doing. I may try to go back to the beta and see how it is working.

I've had the same problem since installing 14.0.1 on my system. Leaving FireFox open for a little while with 7-8 tabs will result it in taking up massive memory and then losing the ability to type in the browser. This applies to the link bar, the search, the CTRL+F find function, etc. It'll take a character once in every 5 key presses, and even that takes a long time.

The only way to fix this is for me to close the browser, then kill the process in Task Manager, then restart it.

What is going on??

Every time there is an update (yesterday Sunday 22 July) we seem to have problems, from this morning some pages will not fully load, while others will. This is not the first time we have had this problem but it was fixed.

I have followed probable problems such as firewalls, that is not the cause we seem to be just sent on a wild goose chase!

I have been with Firefox virtually from the start, but these problems every time there are any changes is getting past a joke, I don't like Chrome so it looks like back to IE, come on Mozilla get yourselves sorted!

I'm on Win 7 Ultimate, and after installing 14.01 I have been getting hangs when downloading - even 50kb jpgs. I've gone into about:config and set plugin.click_to_play to true so thaqt I can eliminate flash files from loading, as Adblock doesn't do this completely. It seems to have helped. I had one download of 1.3mb that failed to download and I had to restart Firefox, then it was fine. I haven't tried many downloads yet, though, because it's only been less than one day. So far, so good, for now.

Sadly that's it for me and Firefox.

I've been with FF since early 2006, but if they're going to release badly broken code and still label it as a "stable release", then they've lost my loyalty. It's broken for me, all other three laptops in the family (all Win 7 but different ages), and as many PC's as I could try it on at work - all reporting the same random freezing. So I'm ditching FF - testing Chrome & Opera at the moment - and so is work. We can't work with a browser that just randomly locks up.

Thanks to all who took the trouble to reply, hope it works out for you guys.

I have this problem too on firefox 14.0.1. It freezes on any site that uses flash. Update after update, Firefox seems to go down the drain. Too bad! Bye Firefox! Hello Google Chrome!

Flash 11.3 has known issues with Firefox, if that is a problem please start a new thread, or read existing threads on the subject. Some users may need to downgrade to the secure FlashPlayer 10.3 or to Flash 11.2.

At one time there was talk of a release 14.0.2 becoming necessary due to startup crashes but it looks like that is now unlikely https://wiki.mozilla.org/Support/Weekly_Meetings/Notes_2012-07-23#Firefox_Status_Update

Over on a post @ http://forums.mozillazine.org/viewtopic.php?f=23&t=2506211 they have discovered that the latest update to the add-on Search By Image (by Google) version 1.0.6 is causing a HUGE MAX CPU use over time.

I had the same problem until i disabled that add-on.

There has been a Bugzilla report made as well

Still here a week after I posted again. It freezes on a page, can't type, and then jumps to another window, so that I can't even find where I was. I've never seen this freezing before. Once it closed a window w/several tabs on it, so annoying, but they came back next time I booted up.

Some people mentioned flash above. This is a combination most of us can't solve on our own - which is why we trust Mozilla to TEST new releases first.