This article covers the situation where Firefox displays a message about crashing when you try to start it.
When Firefox crashes, you may see a window containing one of the following sets of text:the following text:
A number of startup crashes no longer occur in the latest Firefox version. Please update Firefox to see if that addresses your crash.
When Firefox crashes at startup, the possible causes depend on whether Firefox is able to load in Troubleshoot Firefox issues using Safe Mode.
Click the menu button , click help and select Restart with Add-ons Disabled.... Firefox will start up with the Firefox Safe Mode dialog.
If Firefox does not crash when you try to open it in Safe Mode, the most likely cause of the problem is an extension or a theme. Please see our page on Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems for help with this problem.
If you are unable to fix the problem after following the steps on that page, start Firefox in Safe Mode, by following the instructions below:
If Firefox also crashes when you try to open it in Safe Mode, the following sections include information that can help you resolve the problem.
The template "crashsig" does not exist or has no approved revision. @ @0x8fe053f6 Some versions of Hulu Desktop Plugin will cause Firefox to crash on startup. To correct this remove the huludesktop.webplugin file:
Unsanity Shapeshifter is currently not compatible with Firefox 3; it will cause Firefox to crash on startup. You need to disable Shapeshifter until an update is available. You can contact Unsanity about this issue here.
The template "crashsig" does not exist or has no approved revision. GoogleDesktopMozilla.dll@0x5512, GoogleDesktopMozilla.dll@0x5500, GoogleDesktopMozilla.dll@0x56bc or GoogleDesktopNetwork3.dll@0x3dfb
Some versions of the Spector Pro for Windows computer monitoring program can cause Firefox to crash on startup. If you use this program, try updating to the latest version or contact SpectorSoft Support.
Backdoor.Ulrbot.C is a malicious piece of software that can infect your computer and may not be detected by your antivirus program. In addition to installing a backdoor so that your computer is open to all sorts of dangerous manipulation, Backdoor.Ulrbot.C also crashes Firefox 3. The only fix is to manually delete the virus DLL file in Windows Safe Mode. Unfortunately this file has a randomly generated name and size so it may be hard to identify. The following steps detail how to find suspicious DLL files that may be causing this, verify them and remove them if necessary. These steps will only work if you get the Mozilla Crash Reporter dialog box and you have submitted a crash report to Mozilla.
In addition to the specific cases listed above a number of different viruses and spyware may crash Firefox. Ensure that your system is kept clean of spyware and viruses. For more information, see Troubleshoot Firefox issues caused by malware.
If the specific cases listed above do not help, try general troubleshooting of Firefox crashes or get more information about your crash and provide that information when you get help. If you have changed your homepage to not be the default, you may also be experiencing a crash when loading your homepage. In that case, see Firefox crashes - Troubleshoot, prevent and get help fixing crashes.