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Firefox freezes on Win7 Pro x64 followed by reboot-requiring Windows crash

  • 22 replies
  • 25 have this problem
  • Last reply by AmityGames

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First, I am a developer myself, so please provide cogent answers.

Since the last few updates (maybe starting with 51) Firefox is presenting with a terrible issue.

When FF has been running for a while (a day or more) with multiple tabs (<20) and I open a new tab using (+) the tab opens (at the 0,0 position, before the silly animation squeezing the other tabs can play) then the parent window shows NOT RESPONDING FF becomes completely non-responsive After several seconds, Win7 windows explorer crashes (as soon as any other windows event is processed, e.g. when trying to start TaskManager, kill the process, switch to another window...etc). At this point, the PC becomes completely unresponsive, mouse freezes, and requires a reboot

Now, a reboot is a major hassle due to sometimes unsaved data loss and mandatory RAID verification.

FF was my favorite browser, with no corporate bloatware. No add-ons except AdBlocker so that I can listen to uTube without the Geico lizard talking in the middle of my fav song. This being a dev machine, there is zero bloatware or crapware, no pron, not even Flash. Just VisualStudio, antivirus, and FF with uTube+AdBlocker for the music.

FF does not even have the time to generate a dump. Not that I let any app send outbound data from this machine. All the "diagnostic instrumentation" from third parties is disabled.

Come on FF devs, you should know what's going on and fix it. Please give me a browser that's simple and does a few things well. Remember KISS from engineering school? Don't force me to switch to Google/Apple/Muscrosoft spyware....

Thank you

All Replies (20)

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Sorry obviously unsatisfactory and should not be happening.

I suspect this will not be a commonly seen problem or it would have been fixed long ago as a high priority issue. Mozilla should pick up such issue by various methods including: telemetry, user feedback, bug reports, crash & hang reporting.

Have you attempted to rule out your AV & adblocker as potential contributory factors ?

If your crashes are of Windows or Windows Explorer possibly some Windows forum may be better placed to help you.

Have you got access to another machine you could try to reproduce this issue where you do not disable Firefox's diagnostic and reporting abilities. If so it may be much easier to test out the problem write simple Steps To Reproduce and File a bug at mozilla's bugzilla.

OK another tack to take, but it may not be very straightforward The problem occurs after a day or so. Lets make a guess that the problem relates to the state of the Firefox profile. If so make copies of the profile at various times so that you have a profile that is in a state ready to cause issues and your Windows crash. Preserve that profile. Test with a copy of that profile can you now get a problem quickly rather than having to wait a few days. Eventually you should be able to determine what changes within the profile are related to your problems. For instance is it the Session store files or processing of places.sqlite Have you got files within the profile that are locked, are you inadvertently creating multiple files and or profiles. Are you running low on memory availability or at least unfragmented memory.

Also see

If you do file a bug please provide the bug number so we may follow your progress.

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Re-reading your other post in someone else's thread makes me think that you may have already identified the likely cause of your issues as being your AV & or Adblocker.

... /questions/1158873#answer-969021 ... FF in safe mode without AdBlocker is useless ...

Have you considered trying using a different adblocker ?

  • ( Full names and versions please )
  1. What adblocker do you use ?
  2. What AV do you use ?
  3. Have you tried using only
    1. MS Windows AV
    2. The Firefox add on ublock origin

Have you tried contacting the adblocker and AV support sites about the problem ? & if so have is that a public discussion you could link to ?

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Hello, thank you for the answers. Here is the info:

- AdGuard adblocker add-on 2.3.8 - AV Norton Antivirus 2017 (the basic enterprise version, not the consumer spyware bloat)

The only FF addon is the AB, and the only extension is the Mozilla Open264 codec. There is nothing else I really need.

BTW, I don't think the problem is related to the adblocker, or just to me. There are manyother people who complain online of FF freezing their machine. FF cannot generate a report in this crash, so this is why you probably do not receive enough info on it. And it is really not Windows fault this time, since the FF error causes something - maybe memory or message queues - to go so wrong that the Win UI crashes afterwards.

Given the triggering event, I suspect it has to do with either tab animation, or with building the tiles of sites visited.

Please do not be like Windows, who's turned into a monster by adding tons of "cute" features that are really useless. And Linux is going sadly this way too. I just need a simple browser that lets me play music and bypass the ads while I do my work.

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Not sure I can help other than to suggest you file a bug, preferably of a problem where AD blockers and AV are not involved.

Yes Linux is getting more like Windows & Firefox has lots of features that probably are not essential. Of course we all use GUIs not CLIs now and everyone considers it normal to use multi media on the Internet. The Firefox ESR channel was initially intended for enterprise use but may be more suitable for your needs. Some of us will empathise with your views but this is not the place to discus Development decisions.

Yes freezes or hangs are harder to track, but there is still the telemetry that tracks that and also manual feedback & bug reports. Additionally if the problems occur and prevents proper shutdown they may well trigger a timer to generate a Firefox crash report. (However I note you say one is not successfully generated in your circumstances)

I did not see mentin of AdGaurd causing problems. Not too sure though if you are using the most up to date version ? I am looking from Linux but I think the latest Firefox addon is add-on AdGuard 2.5.11 /adguard-adblocker or apparently a Windows executable AdGuard 6.1 AdGuard I did find a 2015 rambling thread

There are often Firefox issues relating to security software. IBMs Trusteer is yet again still crashing Firefox and Norton with a Malwarebytes recently seemed to cause issues e.g. /questions/1157665

If you wish to report problems or file a bug you have a much higher likely hood of it being investigated if you a re able to test and reproduce just in the basic Firefox without the Ad blocker & AV - unless of course, your aim is to prove that combination is a problem.

You speculate there may be memory issues, presuming you have plenty of RAM then as you do not use FlashPLyer try the 64bit version of Firefox maybe the 64bit ESR

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John99 said

Not sure I can help other than to suggest you file a bug, preferably of a problem where AD blockers and AV are not involved. ....

Hello and thank you for the reply.

Did some more testing and this is what the evidence shows:

1) Crash specific to 53 2) Crash triggered by new tab opened by the (+) button. 3) Opending new tabs from within existing tabs does not cause crash 4) Crash NOT correlated to AV or add-ons

IDK how to file a bug from here, and spent a lot of time on this already. I will just condition myself to not click on the (+)

I hope the dev team reads feedback and will try to see what was changed in 53 to lead to this.

I appreciate your willigness to help, and don't want to get into a dev discussion on features. I'm not advocating returning to CLI, just focus on the essentials .

Less features = Slim Code = Ease of Maintenance Just ask Microsoft about it :)

If you were to discover that the crash is caused by the animation of the tabs, you'd probably agree...

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The problem is I do not think others are reporting this hang|crash on opening a New Tab issue. I do not think anyone is likely to be aware of this issue yet. The Dev team certainly do not normally actively monitor this forum, but if they did I am not sure anyone else is reporting the same or a similar issue.

Does the Keyboard Shortcut Ctrl+T also cause a problem for you ?

What happens after Windows and Firefox restart

  • Does Firefox restore the session correctly and give you all the tabs from prior to the crash ?
  • Does the new session also crash if you use the (+) or Ctrl+T
    • If it does I am thinking maybe it is the state of your sessionstore files within the profile that is key to this issue.
    • Possibly you and others could reproduce the issue quickly by overwriting the sessionstore files in a test profile with sessionstore files from a problem profile and immediately create the problem.
    • That opens up the possibility of writing Steps to Reproduce, having a test case, and being able to file a bug and track down a regression range.
  • I am happy to do the bug filing so this issue is noticed by Developers
    • IF I can see and reproduce the issue myself.
    • OR if it is clear multiple others are able to see this issue.

Must admit I have not actually tried yet using Windows 7 and Firefox 53. But I have noticed no issues on various Firefox versions between Fx49 & Fx55 using Windows 10 or Linux.

This thread is not getting a lot of views. It only has three votes. Some threads rack up thousands even hundreds of thousands of views

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John99 said

The problem is I do not think others are reporting this hang|crash on opening a New Tab issue. I do not think anyone is likely to be aware of this issue yet. The Dev team certainly do not normally actively monitor this forum, but if they did I am not sure anyone else is reporting the same or a similar issue. Does the Keyboard Shortcut Ctrl+T also cause a problem for you ? What happens after Windows and Firefox restart
  • Does Firefox restore the session correctly and give you all the tabs from prior to the crash ?
  • Does the new session also crash if you use the (+) or Ctrl+T
    • If it does I am thinking maybe it is the state of your sessionstore files within the profile that is key to this issue.

Thank you for the reply.

Yes - FF remembers pre-crash state correctly and can restore it.

No on profile - I removed the profile and started with a virgin one, but the crash still happened.

I agree on views ... but number of views is not necessarily representative of significance (although Kim K and countless kittens would disagree :)

Scanning the forums, there are a number of other people with this issue, but they are scattered and hard to find.

It is hard for me to reproduce the problem intentionally - any crash costs me time as I have to wait for a RAID verify. I do my best to avoid clicking on (+) and have pretty much conditioned myself to avoid it completely.

It's a pity, FF was one of the few pieces of software out there that's different from the abomination of things like Win10 / Chrome / the iApps

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I was redirected here by John99 from my thread [] .

MAYBE (a big one), this is all caused by the recent published Windows 7/8 DOS $MFT-problem?

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You have marked the thread as solved. If you still have problems it may be better to unmark the solution. (Or you may wish to leave it marked solved as that actually makes the thread more prominent - I will leave it for you to decide - it should show in external and simple internal searches whilst it is marked as solved.)

Have you any second machine or an alternative machine someone else will let you use to test this out. If just using the + button reliably crashes Firefox, and you are sure it is version dependent that means you can write a pretty simple STR as a testcase, and you will then be able to file a bug based on that and you will even be able to use the mozregression tool and so pin down the regression precisely enough for engineers to figure out the change that causes this.

Have you found anyone else who is able to reproduce this issue and preferably who is able to file a bug and use mozregression and add that information to such bug report.

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I am getting the same problem as the OP. I am not sure if has to do with Firefox handling certain scripts on websites or what... but Firefox will stop responding... and if it doesn't recover (sometimes it does) then Windows 7 will freeze and you will have to reboot your computer.

From my experience this doesn't seem to have anything to do with how many tabs are open.

Also, I originally believed that it had to something to do with Firefox being open all day... but I just had a freeze this morning after only turning on my computer and using it for 20 minutes. Only 2 tabs were open when this problem occurred.

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Hi Spywriter, Thanks for your input on this issue.

However this thread was marked solved by the poster AmityGames and if you need a solution to your own problem you would do better by asking your own question.

  1. Please use /questions/new
  2. Try your best to add the troubleshooting information requested as you post the question
  3. Post back here to say you have posted your own question and we will look for it.

Note that sometimes when problems occur at closedown of Firefox they could have knock on effects for how Firefox starts up and possibly even affect how it runs.

Update Edit Looks like potentially a Windows 7 specific issue. I am using Linux or Windows 10 at present - will have to try testing on Windows 7 it appears. Looks like Tonnes has reproducible problems probably something that mozregression may be used on to pin down the regression.

Modified by John99

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Luckily this question is currently marked as unsolved if I saw that right, so posting here.

I have reasons to believe there is a serious issue in latest Firefox releases that may recently have been solved in a current Nightly version, but it causes several and similar questions on this support forum. The mutual factor is mainly Windows 7, and possibly a known graphics chipset. To be short: for the first time ever, I can no longer use a current Firefox release version as of 54 due to very poor performance, and recent versions became harder to use at every release. The only thing that fixed it for now was creating a new profile AND using Nightly, and almost forgot Firefox can be as fast as it is now.

In order to be sure we suffer the same and before pointing to related bugs, I’d like to have answers to the following, as posted in other questions:

Could you please open the Browser Console in the Tools > Web Developer menu and look for specific error messages as soon as sluggishness or other performance issues start? Make sure to select Logging (only or at least) and especially look for ones starting with the following:

Could not write session state file Error: TypeError: invalid 'in' operand exn Could not write session state file Error: NS_ERROR_OUT_OF_MEMORY: Handler function threw an exception: [Exception... "Component returned failure code: 0x80040111 (NS_ERROR_NOT_AVAILABLE)

Also: - Is your Firefox set up to use a proxy server or a .pac file to do so? - What is the manufacturer of your graphics chipset or card? - Do you suffer slow or bad session restore at every startup?

If you are willing to do so, please try a Nightly 55 or 56 build from here (installer) or here (zip), launch that instead of version 53 or 54 but with the same current Firefox profile or a copy of that profile, and report back how things go.

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I've been having the same lockup on opening a new tab as well with FF 53.0.3. The whole laptop locks up requiring a reboot. I'm also a developer. I do not think these lockups have anything to do with a specific website or ad blocker or any add ons. Using Windows 7 64-bit. Today I had a slightly different scenario occur using New Private Window instead of the + to open a new tab. I went to 1 website (replicon) to fill out my time card from Friday. I closed that tab. No website open, just the "new tab" with thumbnails of my favorite sites. I did File->New Private Window. FF did not open the new window and instead the FF window went to Not Responding (same was I have been getting clicking the + to open a new tab). Usually, I can click 1 or two times on other things, then even the mouse locks up. So this time, before clicking anything, I did CTRL-ALT-DEL and it came up to the blue screen where I selected Task Manager. It went back to the desktop, but no task manager came up and laptop was completely locked up. So, New Private Window also causes a complete lockup just like opening new tab.

Another new wrinkle/side-effect post-lockup - After a hard reset, firefox was still not responding. I could not open any sites either clicking thumbnails or typing URL. I cleared the cache and history for last hour. Still not responding. I finally clicked + to open a new tab and closed the first tab. Then, I could click on a thumbnail and it opened the site.

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If this is nothing to do with addons or adblockers then you should be able to reproduce the issue in a clean Firefox profile and with no adblockers or addons installed.

Could I suggest you post your own thread about this issue and try to write out Steps To Reproduce we will then be able to file a bug.

Do you see any of the error messages that Tonnes is mentioning ? and have you tries to see what the profiler picks up as Firefox slows or freezes ?

I do note you provided a solution to one persons lockups

  • I traced the issue to Microsoft .NET 4.5.1. I uninstalled .NET 4.5.1 and all of its updates, and I have no more lock ups. /questions/1158741#answer-973816 (Last month)
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Still having this same problem with Firefox 54....

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If anyone suffering freeze issues (either for Firefox or Windows) did not come to the point of using a new profile yet OR did so but the issue quickly returned, there’s 2 quick things to check and try in order to rule them out as a possible trigger for running into other issues:

  • When Firefox is closed, see if a sessionstore.js file exists in the profile folder. If there is not, something is probably wrong with session storage in the first place. If there is one, delete or move it elsewhere.

Allowing Firefox to start up with a new session using Show your home page in the Start Page settings and not clicking Restore Previous Session, then closing it once without any windows or tabs open should result in a small kind of default file, which is basically similar. Do not attempt to restore this file or any backups of it from a sessionstore-backups folder (in case of a new profile or before starting Firefox again), or clear/move that folder’s contents entirely. The sessionstore file(s) apparently can be corrupt even without noticing it by the number of tabs - even in backups - and cause lots of issues like these. Although I did not suffer Windows hangs or reboots, it did in fact cause my ongoing Firefox hangs and Browser Console messages mentioned above in the past few releases that seem to make it run into memory issues.

  • When Firefox is closed, have a look at the webappsstore.sqlite file in the affected profile. Take note of its size (it should not be larger than a few MBs) and delete or move it elsewhere. There have been reports of this file causing issues such as slow UI responsiveness. It exceeded 10MB in my copy and may have been part of my problem.
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Tonnes said

...If anyone suffering freeze issues (either for Firefox or Windows) did not come to the point of using a new profile yet OR did so but the issue quickly returned, there’s 2 quick thing

Hello, and thank you for following up on this. More and more people are reporting the freeze problem.

I can tell you that the profile and sql store files may be a false lead. Early on, I had read about it, purged these files, and FF53 crashed/froze upon pressing (+).

The dev team changed something fundamental in 53. The change log should be the starting point of tracking the bug.

I cannot reproduce the crashes because I've simply stopped using (+) to create new tabs. As I said earlier, a crash results in a total wipeout, and requires hours of RAID rebuild. I have a lot of work to do and cannot debug FF here.

It's a pity that the FF devs have chosen to build a browser that tries to be everything to all people (like Miscrosfot) instead of focusing on a simple and robust platform for doing few basic things well.

Features like themes...etc can be left on to extension writers. Too much extraneous code is hard to maintain, and probably trying to fix some cutesy feature in 53 led to this fundamental flaw.

Imagine - your machine is totally wipedout because you opened a new tab. And that behaviour may be the result of someone trying to fix the purple yoga theme for the google sketch-it support (just making it up, but I hope you can see my point).

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Are you using the tiles on the "new tab" page?

If so, could you please try using NoScript: Install it, restart the PC, then do whatever you'd be doing normally BUT use the "+" to open new tabs and don't allow scripts anywhere.

It's worth a try because if you don't get any crashes then, we'll know at least a bit more. If you still do, I'm very sorry that you have to go through the whole rebuild process but, like I said, it was at least worth a try.

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Neph said

Are you using the tiles on the "new tab" page? ...

Hello Neph and thanks for the suggestion.

New tiles do come up on blank tabs. I don't know how to stop that, and it baffles me that such a feature should be part of FF. Let extension writers decorate the browser with whatever gimmick they want. Let Mozilla focus on a robust and simple platform - which FF53 is NOT.

I cant disable all scripts because I need some to do business.

I will not - and never click on "+" again - because I work nonstop with no sleep and cannot devote time to dealing with OS crashes. If you guys care about your users, you should escalate this to the Dev team who needs to review the FF53 changes log and identify the problem.

Best Regard Ted

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Have you tried this since seem to be working hard. Is a windows trick to make cpu run better. May avoid crashing and if that is already fixed it is still useful if do not know about it already.


You may want to try this: Open the System Folder then Click on left side Advanced System Settings which opens System Properties click the Advanced Tab then click Performance button Settings then the Advanced Tab then Click the Change under Virtual Memory click Custom Size and Change Size to where it says Recommended Size then Click Set and then Click Apply then please Re-boot.

System - -> Advanced System Settings --> System Properties - -> Advanced Tab - -> Change Virtual Memory - -> Custom Size - -> ENTER Recommended Size - -> Set - -> Apply-- > Reboot

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