We're sorry to hear that your Firefox seems to be crashing. Please perform the following steps to give us a crash report ID that helps us find out more about the cause of the crash.

1. Enter about:crashes in the Firefox location bar (that's where you enter your website names) and press Enter. You should now see a list of submitted crash reports.
2. Copy the most recent 5 report IDs that you see in the crash report window and paste them into your forum response.

Thanks in advance for your help!

More information and further troubleshooting steps can be found in the Troubleshoot Firefox crashes (closing or quitting unexpectedly) article.

Thanks for you reply ! Actually, I believe the crash is due to some particular conditions in the interaction between Firefox and the Flash plug-in, since it does not crash every time Flash content is played. Still, the browser crashed on exit 3 or 4 times within less than 24 hours after the update. Sadly, the crash reporter was not enabled when it failed, since my last Firefox crash dates back from 2009 (which tells how remarkably stable it is ! So, I'm not blaming the browser itself, but probably some interaction issue with the plug-in). I will re-enable it in the possibility of a future Flash/Firefox issue again.

At worst, I can wait for a quick bugfix update either from Mozilla and/or Adobe, but if there is any possibility of a temporary workaround, I think it's worth trying finding one :)

Can you try a clean reinstallation of Firefox (Your profile will remain as it is):

See Uninstall Firefox and How to install Firefox on Windows

I did it but it didn't seem to change anything to the problem. I also asked a few friends and they seem to have the same kind of issue when playing Flash content, though for some, the browser seems to crash during a session and not when exiting.

To make sure it's not a crash specific to this computer, I also tried it on another Windows machine (with XP SP3, same version of Firefox and same Flash plug-in and Firefox modules) and got two random crashes as well when reproducing the issue.

I see some other people who read this thread seem to be having the same or a similar issue. If they don't mind posting replies with their crash details too, it would be very helpful :) Thanks !

I'll post my crash report when it fails again !

I'm not getting crashes but simply a complete 'freeze' for a time whenever Flash content appears. My hard disc sounds as though it is about to fly free from the machine..then finally slows to something sensible and a stuttering play occurs ! I'm using Windows 7, FF 15 and Flash 11.4. I expect some pauses in play because my connection is slow..but this does not cause freezing!

Ok, it seems the crash occurs at a very late stage in the program when the browser is closing because even with the crash reporter enabled, it does not trigger it at all. The only message being the standard "This application has stopped working" Windows message offering to try and find a solution or to simply stop the failing program. So, there's no way for me to provide any crash report about this :/

I have to say I don't really understand why it crashes randomly. For instance, yesterday, I used Firefox as normal, and I did see a lot of pages with Flash content without any trouble. And this morning, it crashed on exist at the second session after having vaguely looked through the homepage of Google News.

If it's related to Flash, would it be possible that Better Privacy (that I use massively) might cause a crash on exit when removing all the LSO's if, let's say, Flash is still writing/reading them? My BetterPrivacy module is set to delete all LSO's without prompting on browser exit.

This is all I can provide through the Windows error information :

Failing application name : firefox.exe, version : 15.0.0.4619, date : 0x50382fcd
Failing module name : xul.dll, version : 15.0.0.4619, date : 0x50382f44
Exception code : 0xc0000005
Error offset : 0x001bea47
Failing process ID : 0x5fc
Failing application starting time : 0x01cd89b721eb0bef
Path to failing application : C:\Program Files (x86)\Mozilla Firefox\firefox.exe
Path to failing module : C:\Program Files (x86)\Mozilla Firefox\xul.dll
Report ID : 9c0f224d-f5aa-11e1-a6f9-002421db1db8

Hi, I'm experiencing a similar issue. What security software are you using?

I'm using F secure..

Avira Antivir Premium 2012 here. All up-to-date with the latest engine, definitions, and with the browser protection (formerly Webguard) enabled.

I also thought it might have something to do with it, but it seems the bug also happens in different configurations with other security software.

I encounter this problem consistently. I run Firefox 15 with Flash 11 on 64bit linux. The flash elements load properly and as long as they are left alone, work properly. But on moving my mouse pointer over the flash element and then outside it, Firefox crashes. This can be consistently reproduced.

I suppose it might be a different issue, since the context is different (Linux there). I couldn't tell if the crash problem I had on Windows 7 can occur in the same conditions on a machine running a Linux distro.

I said "had", because it seems the problem stopped occurring after Firefox auto-updated to version 15.0.1. So, so far, I've not experienced any crash with this new version, like those I decribed in the opening post. Maybe the developers fixed it :)

My problem is similar to @johncastree where Firefox disappears from the screen, mouse freezes, and then a few seconds later reappears and starts working again. I checked crash reports and there are none for when this problem occurs. This all started with version 14.

the same issue here. closing firefox 15.0.1 (ff14 ok!!) I become a warning of Vista crash xul.dll. I have 3 addon since 4 years, never had issues. I resolved for one week only reinstalling firefoxwith the offline installer. after a week, another crash today. no solution I guess. bugzilla is unable to reproduce :(

Firma problema:

 Nome evento problema:   APPCRASH
 Nome applicazione:   firefox.exe
 Versione applicazione:   15.0.1.4631
 Timestamp applicazione:   5047f9c5
 Nome modulo con errori:   xul.dll
 Versione modulo con errori:   15.0.1.4631
 Timestamp modulo con errori:   5047f93b
 Codice eccezione:   c0000005
 Offset eccezione:   0010e567
 Versione SO:   6.0.6002.2.2.0.768.3
 ID impostazioni locali:   1040
 Informazioni aggiuntive 1:   40d4
 Ulteriori informazioni 2:   4062ad41ec8067256aa4c5e2b56d3c79
 Ulteriori informazioni 3:   40d4
 Ulteriori informazioni 4:   4062ad41ec8067256aa4c5e2b56d3c79

about: crashes: empty. I hope this helps...

Ok, it looks like the crash reappears as well in Firefox 15.0.1 There's definitely something about Flash and Firefox because it happens very randomly without any reason, but *always* when some Flash content was loaded (be it simply a Youtube video or a random Flash animation). It is still exactly the same type of crash as that I first mentioned here. The crash reporter does not start, there's nothing in about:crashes (in a nutshell the same problem as anuswara posted above).

Wiping the cache, the profile and reinstalling Firefox cleanly does not change anything. I'm pretty sure Flash is the element to be blamed here, but I suppose there could be some adjustments to make in Firefox to address this issue, because, if we have to wait for Adobe to provide a bugfix (they already have issues providing security patches), one can bet the problem will spread.

Can you please try this? This might be a very technical thing, but please try at least: https://developer.mozilla.org/en-US/docs/How_to_get_a_stacktrace_with_WinDbg

Hi, too hard for me this stacktrace!

I will try to reinstall firefox in a different folder. There are a lot days (with 10 tab youtube!) and I dont have this crash of xul.dll. very strage,,,

It were better to file a bug on adobe?? thanks to all.

In reply to anuswara : Indeed, there are days when I can have several tabs with flash content loaded without a single crash for several days. And then, the same content opened in the same conditions, or just one single Flash content can trigger that crash on exit without any reason.

It's random like : No crashes at all for 10 days, and then it's 1 crash per day just out of nothing, always on exiting.

To be honnest, I don't expect any effort from Adobe. So, unless a bugfix in Firefox or at least the reason of the crash be found, there might not be any workaround until the issue has seriously been addressed.

So far, everything I tried failed to prevent that crash from occuring. Even if it's not a blocker thing, it's highly annoying seeing random crash messages while things seem to be working fine.

why the issue arised with the latest flash build??

why the crash disappear if you set ProtectedMode=0??

therefore I spoke about Adobe...