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Firefox keeps "Not Responding" randomly, then comes back after 10-15 Seconds.


Every now and then, when I'm on Firefox it will not respond then the window will fill white and at the top it will say "Mozilla Firefox (Not Responding)".

It responds after about 10-15 seconds but this keeps happening every 2-3 Minutes and is making Firefox unusable to watch videos on Youtube and read other things as when it starts responding it take me back to the top of the page.

I cannot pinpoint which websites this is on but it normally (But not always) happens when I have more than one tab open (Usually on Youtube + SammyServers.com)

Modified by Noah_SUMO

Additional System Details

Crash ID


Installed Plug-ins

  • EA Battlefield Heroes Updater
  • Dassault Systemes 3DVIA Shape Plug-in
  • Office Plugin for Netscape Navigator
  • Adobe PDF Plug-In For Firefox and Netscape
  • nprt
  • NPRuntime Script Plug-in Library for Java(TM) Deploy
  • Default Plug-in
  • Pando Web Plugin
  • Shockwave Flash 10.1 r85
  • GEPlugin
  • Next Generation Java Plug-in 1.6.0_21 for Mozilla browsers
  • 4.0.50917.0
  • Windows Presentation Foundation (WPF) plug-in for Mozilla browsers
  • Google Update
  • Wacom Dynamic Link Library


  • User Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-GB; rv: Gecko/20100824 BTRS25860 Firefox/3.6.9 ( .NET CLR 3.5.30729; .NET4.0C)

More Information

Szarko 0 solutions 1 answers

FireFox version: 3.6.12

OS: Windows 7 x64

I can't believe there hasn't been a response to this problem.

I recently formatted and the problem started a few days ago for me.

You start to download a file, download window pops up, everything freezes 'FireFox' stops responding... If you wait it out a bit say 10-30 seconds it comes back and everything is normal.

It happens randomly, it occurs doing different taks within the browser.

Surely FireFox development team must have some kind of idea what causes this? It's very very irritating.

Some help would be appreciated. Thanks.

njpeters23 0 solutions 1 answers

Helpful Reply

I'm already sick enough of this problem over the past few weeks that I was ready to switch to Chrome, but thought that I would check Firefox support first.

If there isn't a fix soon, I'll definitely be switching. I've not had problems like this with Firefox before, but this is very disruptive.

martijn2011 0 solutions 8 answers

Search for:

places.sqlite (history stuff+favicons etc etc)

urlclassifier3.sqlite (google phishing url's, will be rebuild)

Must be somewhere in your profile directory...DELETE them.

iirebecca 0 solutions 1 answers

I have this problem and it seems that "631" people have this problem aswell

Is anything going to be done about this? Or am I going to have to switch to a new browser? This has been happening to me for over two weeks and updating firefox has not helped.

I even tried what martign2011 had suggested and still have the problem. I did not see a 'urlclassifier3.sqlite' in my profile directory so I am assuming that it's not the problem.

Modified by iirebecca

Sasssysweeet 0 solutions 5 answers

I hope this gets fixed soon. I can't stand any other browser on the market. This problem is seriously delaying my projects. I'm almost out of time on one of them and this a huge disruption. I can't believe that this hasn't been fixed yet given how many people have clicked on here with the same problem. HELP! I NEED MY MOZILLA BACK!!!

justdave7102 0 solutions 1 answers

OK, really? This is so annoying. Firefox has been so good all these years, and I have never switched browsers, but now it seems I am forced to. How can Mozilla not know of this issue ?? Has anyone with 7.0 tried revting back to a previous version? Even as I type this message, the white screen of non responding frustration comes up.... C'mon Mozilla, we want our Firefox back !

  • Top 25 Contributor
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622 solutions 8022 answers

It must be frustrating if you suffer from this problem, and obviously many of you do, although there will be many millions of happy firefox users not seeing the problem.

This sort of problem may well have many potential causes. If you suffer from the problem then may I suggest you start your own thread and detail fully your problem and the troubleshooting efforts you have made.

For general advice also see

If anyone is able to see this problem

  • in Troubleshoot Firefox issues using Safe Mode
  • with all plugins (or all but a named essential plugin disabled - for instance if the problem occurs only with Flash Player)
  • with a limited named set of tabs open
  • (preferably also try it in Nightly, otherwise developers are likely to consider the problem to be already fixed)

Then it may be worth others trying to recreate it in the same circumstances, and file a bug report so that developers may review and fix the problem.

If you consider it appropriate post your own question , and if you think readers of this thread may be interested in the problem or its solution include a cross link in this thread to your new question.

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622 solutions 8022 answers


I would not recommend deleting places.sqlite as a solution. Be aware if you do that all your bookmarks and history etc are at risk. Yes Firefox will try to rebuild places.sqlite, but it will be with older information.

If you do try that I suggest instead copying the file somewhere safe outside the firefox profile, that leaves open the option to copy it back if need be.


This thread may be of interest Mozillazine What is urlclassifier3.sqlite / page infos unusably slow

  • Top 10 Contributor
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10755 solutions 96800 answers

If you delete places.sqlite then you need to remove other existing places.* files like places.sqlite-journal as well to avoid problems.

Make sure that security (anti-virus) software isn't blocking access to files in the Firefox Profile Folder

Schalk 2 solutions 12 answers

Can everyone confirm that you are running the latest 6.2 version of Firefox? A lot of the memory related issues has been fixed. If some of you are still experiencing this problem using version 6, please let me know.

pittsy2004 0 solutions 5 answers

I had this same issue and solved it. The problem was a registry error. Follow the instructions below to resolve it.

Go to 'Run' and open 'cmd' • Type 'netsh' in command console then press enter • Then type 'winsock' and press enter and then type reset • Restart Your PC

• Problem Is Solved :)

Modified by pittsy2004

cumigosong 0 solutions 1 answers

Firefox version: 6.0.2 OS: Windows 7 64 Bit

I was having this kind of problem before, and it really bugged me a lot. And suddenly, it came up to my mind to change the compatibility of Firefox to Windows XP SP 3 and run it as administrator. Up till now, there has not been any "not responding" status no matter how many tabs or what kind of websites I open. Hope this helps.

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Good news for you if it solved the problem.

Another 64bit user I notice. Someone more knowledgeable may comment but I am not aware of reasons running as admin should in itself solve this problem.

That is an easy step to take, maybe others with this problem will try it, preferably with a brand new OS account.

  • Also maybe you yourself may wish to try setting up another new OS account for a new user but not an admin account,
    • does that also solve your not responding problems ?

(I have an XP SP3 but it is 32bit) Not sure if SP3 still has Guest status accounts, but I would avoid using them, they may present unnecessary security risks

N.B. what you do if you change accounts to one you did not use before is effectively clear your cache and cookies and use a new profile, all these actions are part of the recommended Troubleshoot and diagnose Firefox problems steps.

I have seen other computer problems reported as solved by changing browsers, resulting in contradictory reports of which browser works without problems. The salient point was changing browsers started with a blank sheet so to speak, a new cache, and only the initial cookies.

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the OP in a busy thread
I just updated to Firefox 6.0.2 and it is still freezing intermitantly. It lasts for 30-60 seconds. Before the update it froze intermitantly for more than 60 seconds. Help me unfreeze firefox!
reports the freezing problem on a Windows 64bit system was resolved by using the default theme.

jarnaez 0 solutions 2 answers

I have the same issue but have never used anything but the default theme. Only addons are Sage, Adblock plus, No Script, Tab Mix Plus, and Thunderbird biff but I haven't seen anything about those being a problem.

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It is frustrating if firefox is freezing and can not be used properly.

Your own or anyone else's particular combinations of extensions themes and plugins could be a problem. What is known is that many users do not experience this problem. (Even if hundreds mention a problem in a thread remember the userbase of firefox is in 100s of Millions) As far as I am aware no one at all is able to demonstrate (other than users with malware, or with security /firewall problems, or on a problem site) the problem occurs if all the following apply

If anyone can demonstrate that then carefully document it and file a bug yourself, or ask someone to assist you in filing a bug, and as a first step I suggest starting your own thread.

Note users have reported one or more of the above steps solves this type of problem.

Silverrey 0 solutions 1 answers

I can vouch that neither compatibility mode, safe mode, or a fresh format (thought it was a virus) are reliable fixes. With it continuing even after a format I can not think of anything further that can be done on our end to trouble shoot this. If there are any other fixes please tell me.

More info: When Firefox freezes it maxes out one of my processors but leaves the second untouched. I have tried switching which processor runs Firefox (default was both) and again there was no noticeable difference. Even after the update today (9/30/11) it has frozen 3 times while I have typed this.

For those that are having the problem of it going back to the top of the page or refreshing the page: If you notice Firefox freeze do NOT click on it. If you let it sit without clicking on anything it (normally) acts as if the freeze never happened. This only helps if you notice the freeze before you click on anything but at least it is better then nothing.

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possible workaround in some cases see: https://support.mozilla.com/en-US/questions/872283?page=3#answer-254348

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Which version of Firefox do you use?


technogroup 0 solutions 1 answers

Same issue.

Win 7 Ultimate x64

Freezes every 10 minutes for 15-20 seconds at a time. I just noticed it happening last week or so.