How to Know FireFox Crash cause

Extensions

Problematic extensions may cause crashes. Start in Firefox Safe Mode and click "Continue in Safe Mode". This will help determine if an extension is causing the problem, since Safe Mode disables all extensions.

Note: If Firefox also crashes in Firefox Safe Mode, then an extension is not the problem and you should skip to the next section.

• If Firefox no longer crashes when you run in Firefox Safe Mode, go to the Add-ons Manager Extensions list, click the Disable button for every extension, and restart Firefox normally. If the crashes no longer occur when you run Firefox in normal mode with all extensions disabled, one of your extensions was causing Firefox to crash. Try re-enabling them one at a time, to find the problem extension.
• If disabling all extensions and restarting Firefox in normal mode doesn't resolve the crash problem:

In Firefox 4 and above, Firefox Safe Mode also disables hardware acceleration, so the problem could be a video device or driver issue (see below). Try unchecking the option to use hardware acceleration in Firefox ("Tools -> Options -> Advanced / General").

Firefox Safe Mode also disables the JavaScript JIT compiler. In Firefox 4 or above, try setting javascript.options.methodjit.* preferences to false in about:config ( see below).

Other installed software

Other installed software that is running on your computer may be causing Firefox to crash, including:

McAfee SiteAdvisor

The SiteAdvisor component included with McAfee's Internet security software can cause Firefox to crash at startup, among other problems. (See also this blog post on a memory leak issue with the SiteAdvisor add-on.) Even though McAfee SiteAdvisor is installed as a Firefox extension, if Firefox crashes at startup you may not be able to remove or disable it from within Firefox Safe Mode. To resolve the problem, you can remove SiteAdvisor using the McAfee uninstaller (see McAfee's article, How to uninstall SiteAdvisor for details). Note: Some versions of McAfee SiteAdvisor are already on the Add-ons Blocklis

NVIDIA Network Access Manager

The NVIDIA Network Access Manager, an optional application for network security included with some NVIDIA products, can cause Firefox to crash unexpectedly. An easy workaround is to uninstall or disable this program and use another firewall, such as the built-in firewall included with Windows 7.

Roboform

The RoboForm Password Manager application for Windows can cause Firefox to crash; for example, older versions would crash at (or close to) startup (RoboForm 7.6.1 and below, now blocklisted in Firefox 8 and above) and recent reports show that RoboForm 7.7.3 causes random crashes. If you need this application, check for an updated version on theRoboForm for Firefox page or from http://www.roboform.com/download.

Spector Pro for Windows

Spector Pro for Windows computer monitoring software can cause Firefox to crash at startup or when opening a new tab. If you use this product, try updating to the latest version or contact SpectorSoft Support.

ThreatFire

PC Tools' ThreatFire anti-malware software can cause Firefox to crash at startup. Try updating ThreatFire to a newer version or uninstall it. Note: If you have both ThreatFire and Avast software installed.

Trusteer Rapport

Trusteer Rapport (an application promoted by some banks for malware protection) may cause Firefox to crash. If you use this software, try disabling it

On Windows: Go to "Start->All Programs->Trusteer Rapport->Stop Rapport"

On Mac: Go to "System Preferences -> Other -> Rapport -> Stop Rapport"

If that stops the crashes, try updating the software to the latest version, uninstall the program if you don't need it.

ZoneAlarm ForceField

ZoneAlarm ForceField (either standalone or included with ZoneAlarm Extreme Security) may cause Firefox to crash on certain websites or crash at startup. Try clearing the ZoneAlarm virtual cache (depending on ZA version, go to "Browser Security -> Settings -> Advanced" or "Internet -> Web Security -> Settings") then click "Clear Virtual Data" and restart Firefox. If you still have problems, turn off Forcefield (in ZA Extreme Security, go to "Internet -> Web Security -> Settings -> Advanced Settings", and turn off "Enable Virtualization"). Note: If Firefox fails to start after an update, see Firefox does not start after updating with ZoneAlarm ForceField enabled.