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Firefox crashes at startup after update

  • 4 replies
  • 2 have this problem
  • Last reply by jscher2000

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I just updated firefox to the latest version and it will not open as it crashes prior to opening. I have tried safe mode and it still crashes. Scanned for viruses and malware and nothing was found.

Crash ID: bp-2120293e-8c56-47a7-86ac-832622151103

All Replies (4)

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Hmmm if Safe Mode doesn't work, it could still be a Plugin. I think there was something problematic in 41.x that was getting fixed in 42.

42.0 is out, any help there?

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Updated to 42 with the same result. Still crashes at startup, even in safe mode.

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Okay, what's your antivirus solution? I can see a bug related to the crash report that points to Websense Endpoint causing this behaviour. Websense version support comes a few versions behind it seems.

Other than that, I would try removing plugins like Java and Flash altogether before trying Safe Mode again.

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Hi texasdomer, sorry to hear about the crashes, and thank you for the report link.

There is a reference in your report to a compatibility problem with the business security program Websense Endpoint, but from your crash, it looks like you using Norton or Symantec software. If that's true, could you run LiveUpdate several times to make sure you have the latest update?

Does this occur every time you start Firefox, or do you notice any pattern related to the problem?

If you could post a few more recent report IDs maybe that would help identify the problem.

Since you already have tried Firefox's Safe Mode, and there' s not an obvious culprit, you may want to try the following next:

Clean Reinstall

We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent, corrupted, or alien code files). As described below, this process does not disturb your existing settings. Do NOT uninstall Firefox, that's not needed.

(A) Download a fresh installer for Firefox 42.0 from to a convenient location. (Scroll down to your preferred language.)

Note: If you prefer to wait on installing Firefox 42, which is just out today, you can find a link to Firefox 41 in this article: Install an older version of Firefox.

(B) Exit out of Firefox (if applicable).

(C) Rename just the current program folder, either:

(64-bit Windows folder names)

C:\Program Files (x86)\Mozilla Firefox


C:\Program Files (x86)\OldFirefox

(32-bit Windows folder names)

C:\Program Files\Mozilla Firefox


C:\Program Files\OldFirefox

(D) Run the installer you downloaded in (A). It should automatically connect to your existing settings.

Does Firefox work more normally?

Note: Some plugins may exist only in that OldFirefox folder. If something essential is missing, look in these folders:

  • \OldFirefox\Plugins
  • \OldFirefox\browser\plugins

Otherwise, there's no reason to keep the old folder except research/curiosity.