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Firefox 30 won't start, hangs after closing (Bug1004476)

  • 55 uphendule
  • 120 zinale nkinga
  • Igcine ukuphendulwa ngu John99

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Hello, everyone!

I've filed a bug report here: The problem is that after installing Firefox 29 with no profile at all and installing any addon that requires a browser restart (NoScript for e.g.) Firefox restarts OK, but after closing it and trying to open again I get a message: "Firefox is already running". I can see in the Task Manager that there is already Firefox running in the background. I've found several people complaining about this issue. Here: And here:

Thank you in advance

Modified May 13, 2014 11:01:46 PM BST by John99

2nd Update. (Comment by a moderator)
Engineers are working on issues that have been identified.
The known issues are problems with Firefox hanging on closedown resulting in Firefox not restarting unless the hung process is killed.

Workaround ensure Firefox is NOT set to clear History on Close down
Use NewButton New Fx Menu → Preferences → |Privacy| Firefox will: [Remember History v ]
See also my post downthread /questions/997918?page=2#answer-572501 ~J99

 Modified June 5, 2014 12:26:07 AM BST by John99

3rd Update

A fix is now on the Beta Channel Fx30b8 hopefully in a couple of weeks that will be on everyone's Release of Firefox30.

Okulungisiwe ngu John99

Isisombululo esikhethiwe

Strange, but I cannot reproduce this isssue anymore. Maybe there was something wrong with my profile when I accidentally reproduced it under Firefox 30. I dunno. Really strange.

Well, if it doesn't affect anybody else I think it's time to close this thread.

Funda le mpendulo ngokuhambisana nalesi sihloko 👍 0

All Replies (20)

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Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

  • Do NOT click the Reset button on the Safe Mode start window.

You can also check for issues caused by plugins ans disable all plugins (Never Activate)

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Judging from the System Information aside you appear to be using Firefox 24. Have you tried using Firefox 28 which is now the previous Release ? Does everything work as expected in Fx28 ?

Did you also mention elsewhere that you have a very similar problem when using Firefox on Linux.

Details of your current troubleshooting information may give some clues. Could you paste that in to your next reply from the troubleshooting information page please. There is a button for copy text.

Even if this issue is due to a Firefox bug it is not going to be fixed or even investigated as a bug in an unsupported Firefox 24. May I suggest that you try installing the current Release Firefox 29. If you do a custom install and create an additional new profile you will be able to keep the working but insecure Firefox 24 or Fx28 whilst troubleshooting Fx29.

What security related or cleanup type software do you run ?
Just in case that turns out to be significant. If you are seeing problems on both Windows & Linux is any of such software common to both machines /OS ?

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This could of course be a Firefox 24.5.0 esr version (Help > About) as we can't see this from the user agent.

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Thanks cor-el

Bug shows

User Agent: Mozilla/5.0 (Windows NT 5.1; rv:24.0) Gecko/20100101     Firefox/24.0 (Beta/Release)

Build ID: 20140421162246

So I guess you are correct.
The (Beta/Release) I took to indicate it was an outdated Beta, but I should have looked at the date,

For comparison My 64 bit Fx24.5.0 is Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Firefox/24.0 ID:20140421162246 CSet: 1c35a9dca8a0

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Please stop guessing about the version. I know what I'm talking about. The problem is with Firefox 29. I just rolled back to the stable 24.5.0 ESR which works for me. This happens in Debian Wheezy and in WinXP. There is a bug report link in my topic as well as other people complaining. Go search the forums and you will see. Anyway thank you. Will be using ESR version.

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Maybe now you have a working Firefox you have lost interest in this issue.

First of all thanks for reporting this.

Sorry, I know it must be frustrating to find a fault and then not get it fixed straight away when you report it. Many people would not even take the trouble to do that they would just leave it to others. At Firefox a lot of those "others" are you and me, the Firefox users taking an interest in Firefox.

I will try to expand on something of the bug hunting and fixing process it will explain why we are guessing at your information.

The version is important.

Bugs only make progress once they are reproducible. Otherwise there is nothing to ask engineers to work on. Steps To Reproduce (STR) are important.

Bugs are only investigated if they affect a supported version of Firefox.

If you have no problem on Firefox 24 ESR but you have a problem on Fx29 you may have discovered a regression. That would be investigated but it is most likely to progress if you can help us to demonstrate the issue.

Regression Range
The next stage after getting successful STR is to pin down a regression range. To know where to start it is handy to know which major version the fault appeared in first. You are suggesting this is Firefox 29, that is why I asked whether you have tried in Fx28 and it is trouble free.

With STR and an approximate Regression Range there is a utility that may be used to semi automate the regression testing and workout the change-sets involved. Now we are able to say to engineers. We have hound a fault do this 1,2,... to test for the existence of the fault, and take note that the fault appears to have originated in these changes a,b, ....

Have you lost interest in this issue as you are now using ESR.

The environment and other related software is also Important

Clearly this bug does not affect everyone. What are the critical factors meaning you see and reproduce the issue but others do not ?

For instance did the fault actually occur in Firefox 29, or was this just coincidence ?
Could one causal factor have been a Debian update or some other software ?
That may explain why not everyone sees the problem.

Sorry I am not testing on Debian or on XP.
Maybe others on Debian or on XP are able to reproduce.

Is anyone watching this thread or the bug able to reproduce ?
If so please join in, confirm STR and provide what information you can towards helping with this.


Meanwhile even if the cause of the problem is not yet determined will killing processes allow Firefox to restart and thereafter behave as normal ?

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Sorry, I really have no time investigating upon this issue. All I need is a working browser. Now I'm leaving this to other people, but will visit this and other forums. Here is a Mozilla forum thread going on, btw:

Here is another article upon this issue with a temporary fix:

Actually, a temporary fix is to disable "privacy.sanitize.sanitizeOnShutdown" config option. I forgot, this was the first thing I switched on in about:config after installing Firefox along with disabling the disk cache.

Thank you for your support, Mozilla!

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"Seems the history, cache et al files are locked out when you exit so Firefox can't delete their contents and stays running in background, even if you relaxed security settings. The only viable solution was to be to leave 'Firefox will Remember history' alone then manually delete contents when necessary using History > Clear Recent History in the Menu Bar"

Hope it would help you reproduce this issue.

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Clearing cookies via "Clear history when Firefox closes" is a possible cause of hanging issues as that makes Firefox also clear cookies from plugins.

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hello TheExplorer, a wild guess: could you try it with "privacy.sanitize.sanitizeOnShutdown" on and "network.seer.enabled" off for testing purposes? thank you...

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Well, tried what you suggested. Everything is OK. But... I'm a bit puzzled and now I think that 'browser.cache.disk.enable' is the culprit.


1) unpack Firefox-29.tar.bz2 into /opt dir 2) launch it, go to about:config 3) switch on 'privacy.sanitize.sanitizeOnShutdown' 4) install NoScript for e.g. It asks to restart. Restart 5) switch off 'browser.cache.disk.enable' 6) close Firefox and try to open it again.

Can anyone confirm please ?

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i cannot replicate it with those steps under windows (and have found no reliable way to reproduce this problem yet).

my theory was something else: there was a new predictive network action database introduced in firefox 29 (which can be disabled via network.seer.enabled). since apparently there are still some performance issues with it (bug #966469), it was a guess that clearing history on shutdown will also trigger a clearing of this db which may be deferring the proper shutdown...

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Hi again The Explorer,

Consider creating an additional test a profile with default prefs. Prefs may be set to default by deleting the file prefs.js (and rename any user.js)

By trying that method

  • You may be able to quickly determine what variation of prefs from default cause this issue.
  • It is probably a simpler STR , one that more users are willing to try, and is applicable across different OS s
    • In fact without creating a new profile just temporarily renaming the files prefs.js & any prefs.js.mozten and user.js would be a useful test to prove prefs are involved with this issue.

It may also help to know what addons you have installed as that could be affecting this.

Okulungisiwe ngu John99

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I guess now that something is wrong with sanitizing history while disk cache is disabled. Maybe it's got to do with some Linux Kernel memory handling. I dunno. Gonna try it in Windows XP (never did actually as I prefer Linux).

Well, if I reproduce it under WinXP then I'll give up :( I really have no time testing it. Just found an issue and decided to post it here and in the bugzilla.

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Yes. I've also successfully reproduced it under WinXP SP3, 32-bit. No antivirus. Almost fresh installation.

You even don't need any extension to be installed. Here are the steps. REAL STEP BY STEP GUIDE. Exactly what I did:

1) There should be no profile at all (including any other hidden folder where Mozilla can reside like Application Data, Local Settings etc.) 2) Install Firefox 29 (en-US) 3) Launch it, open Settings. Here is what I always do after installing FF: 4) Then open about:config and set one after another these options:

browser.tabs.closeWindowWithLastTab = false
browser.sessionhistory.max_entries = 10
browser.sessionstore.max_tabs_undo = 3
browser.sessionstore.resume_from_crash = false
browser.bookmarks.max_backups = 1
browser.cache.disk.enable = false
network.dns.disableIPv6 = true
geo.enabled = false
browser.urlbar.trimURLs = false
edit formatted with pre tabs. ~J99
AND browser.cache.disk.enable = false

That's all. Close Firefox and try to open it again.

That's all I do to reproduce it in WinXP and Debian Wheezy. Sorry I didn't write about these steps at first.

Okulungisiwe ngu John99

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Sorry! I forgot the last config option !

browser.cache.disk.enable = false

Sorry, guys. I think it does the job.

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I think a bundle of disabling 'browser.cache.disk.enable' and enabling 'privacy.sanitize.sanitizeOnShutdown' does the job. I can be mistaken though.

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I may be able to reproduce now, but I don't think all those prefs would need to be set, and I tried before you added browser.cache.disk.enable = false

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Yes. No need, of course, to set all these options. I thought 'browser.cache.disk.enable' or 'privacy.sanitize.sanitizeOnShutdown' did the job. It was just a guess as a result of some googling.

Glad that you could reproduce it.

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