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Firefox crashes

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  • 6 have this problem
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  • Last reply by cor-el

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For the last several months Firefox has repeatedly crashed. I've sent info on the crash pop-up, but its gotten worse. Yesterday it crashed twice-- once when I wasn't even using Firefox. I've followed you step-by-step and updated software, pull-ins, scanned for viruses, etc. I am running Windows 8 and Java is out of date, but after downloading the updated software a Windows pop tells me I can't run this software on my computer.

There is nothing consistent wit the crashes -- I can have one window open, using a few tabs or I can have one window with a large number of tabs open-- it still crashes. The last time Firefox crashed I wasn't even using the browser.

I'm to the point of dumping Firefox, but I LOVE your browser and have been using it for a decade or so. Would reinstalling the browser help?

Thanks Tom Dowling

PS One other thing: The browser also constantly slows down until a popup appears about running some script-- once I click disregard (or whatever) things then run slowly again.

For the last several months Firefox has repeatedly crashed. I've sent info on the crash pop-up, but its gotten worse. Yesterday it crashed twice-- once when I wasn't even using Firefox. I've followed you step-by-step and updated software, pull-ins, scanned for viruses, etc. I am running Windows 8 and Java is out of date, but after downloading the updated software a Windows pop tells me I can't run this software on my computer. There is nothing consistent wit the crashes -- I can have one window open, using a few tabs or I can have one window with a large number of tabs open-- it still crashes. The last time Firefox crashed I wasn't even using the browser. I'm to the point of dumping Firefox, but I LOVE your browser and have been using it for a decade or so. Would reinstalling the browser help? Thanks Tom Dowling PS One other thing: The browser also constantly slows down until a popup appears about running some script-- once I click disregard (or whatever) things then run slowly again.

All Replies (2)

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Hi Tom, in order to connect forum volunteers with the crash reports you have submitted, we need the ID numbers. Please check the support article "Firefox Crashes" (especially the last section) for steps to get those crash IDs, and then post some of the recent ones here.


To test whether any of your extensions might be contributing to the slowdown, have you tried visiting the same sites in Firefox's Safe Mode? That's a standard diagnostic tool to bypass interference by extensions (and some custom settings). More info: Diagnose Firefox issues using Troubleshoot Mode.

You can restart Firefox in Safe Mode using

Help > Restart with Add-ons Disabled (Flash and other plugins still run)

In the dialog, click "Start in Safe Mode" (not Reset)

Any difference?

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Note that your System Details List shows multiple Flash plugins.

  1. Shockwave Flash 12.0 r0
  2. Shockwave Flash 11.9 r900
  3. Shockwave Flash 11.8 r800

You can find the installation path of all plugins on the about:plugins page.

You can check the Flash player installation folder for multiple Flash player plugins and remove all (older) version(s) of the plugin (NPSWF32) and (re)install the latest Flash player.

  • (32 bit Windows) C:\Windows\System32\Macromed\Flash\
  • (64 bit Windows) C:\Windows\SysWOW64\Macromed\Flash\

Your System Details List shows that you have a user.js file in the profile folder to initialize some prefs each time you start Firefox.

The user.js file is only present if you or other software has created it, so normally it wouldn't be there. You can check its content with a plain text editor if you didn't create this file yourself.

The user.js file is read each time you start Firefox and initializes preferences to the value specified in this file, so preferences set via user.js can only be changed temporarily for the current session.

Delete a possible user.js file and numbered prefs-##.js files and rename (or delete) the prefs.js file to reset all prefs to the default value including prefs set via user.js and prefs that are no longer supported in the current Firefox release.

You can also consider to try a new profile to test if your current profile is causing the problems.

See "Creating a profile":

If the new profile works then you can transfer some files from an existing profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over the problem