Firefox crashes

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This article deals with Firefox closing unexpectedly, or closing after an error dialog (e.g., the Mozilla Crash Reporter) appears.

  • If Firefox hangs, freezes, or stops responding to user input but does not close, see Firefox hangs.

If Firefox is crashing, first make sure you are using the latest public release version of Firefox, which will have the most recent fixes. You can download and install the latest version of Firefox from or you can use the Software Update feature from within Firefox. You may also wish to review the Firefox release notes for your Firefox version, to see if the issue and solution is listed under "Known Issues".

Crash logs may help you to locate the problem. See Crash reports, below.


Problematic extensions may cause crashes. Start in Firefox Safe Mode and click "Start in Safe Mode" ("Continue in Safe Mode" in Firefox 14 and below). 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. Try setting the javascript.options.*jit.* 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. In addition to the products listed below, Firefox crashes can be caused by Internet content-filtering or parental control software such as SafeEyes, McAfee Family Protection and similar products. If disabling the software stops the crashes, contact the product's support site see if there are any program updates or settings you can change to work around the problem (or uninstall the program, if you don't need it). [1] [2]


BitDefender security software can cause crashes, particularly in Firefox 14 (Firefox 15, in Beta at time of writing, reportedly crashes much less frequently). A recent BitDefender automatic update should have fixed the problem so, if you use this software, make sure that the relevant BdProvider.dll file is version (or above). The system should be restarted after the BidDefender update to insure that the program is using the updated files. [3] [4][5] [6]


BitGuard software by MediaTechSoft Inc. can cause Firefox to crash frequently or Firefox may crash at startup (bug 925459). BitGuard is bundled with toolbars or other software; if installed, you will see BitGuard.exe running in the Windows Task Manager. To resolve, remove this software via Windows Control Panel and check for malware. [7] [8] [9] [10] [11]

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 Blocklist. [12][13][14] [15]

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. [16] [17] [18]


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 the RoboForm for Firefox page or from [19] [20] [21]

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. [22] [23] [24]


PC Tools' ThreatFire anti-malware software can cause Firefox to crash at startup. Try updating ThreatFire to a newer version or uninstall it. [25] [26] Note: If you have both ThreatFire and Avast software installed, see this article.

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 as follows: [27]

  • On Windows: Go to "Start -> All Programs -> Trusteer Endpoint Protection -> Stop Trusteer Endpoint Protection"
  • On Mac: Go to "Apple menu -> System preferences -> Other > Trusteer Endpoint Protection > Stop Trusteer Endpoint Protection"

If that stops the crashes, try updating the software to the latest version, uninstall the program if you don't need it, or contact Trusteer Support. [28] [29] [30] [31] [32] [33]

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"). [34] [35] Note: If Firefox fails to start after an update, see Firefox does not start after updating with ZoneAlarm ForceField enabled.

Crash when starting Firefox

Crashes that occur when starting Firefox are difficult to troubleshoot, especially if you also cannot start in Firefox Safe Mode. Make sure you allow the Mozilla Crash Reporter to submit a crash report so that you can view it later to get any useful information about the crash, including related bug reports (see viewing crash reports).

Note: If Firefox doesn't start up but you aren't sure whether it crashed or not and you didn't see the Mozilla Crash Reporter, see also Browser will not start up.

If Firefox does not crash when you restart in Firefox Safe Mode (at the "Firefox Safe Mode" window, click "Continue in Safe Mode" or, in Firefox 15 or above, "Start in Safe Mode"):

  • The crashes may be caused by Problematic extensions, which are disabled in Firefox Safe Mode. To see if an extension is the problem, go to the Firefox "Add-ons -> Extensions" list, disable all of your extensions and then close and restart Firefox. If Firefox starts normally, one of your extensions was causing the crash. [36]
  • If it still crashes after you disable all extensions and restart Firefox normally, the problem could be with the graphics content of your Firefox startup page and/or a video device or driver issue (see below) since Firefox Safe Mode disables hardware acceleration in Firefox 4 and above. Try restarting in Firefox Safe Mode and turn off hardware acceleration in Firefox Advanced settings (Options -> Advanced / General (tab)"). [37]

If Firefox also crashes when you attempt to restart in Firefox Safe Mode:

  • Problems with Firefox program files can cause Firefox to crash at startup, even in Firefox Safe Mode. To resolve, reinstall Firefox. If the startup crashes persist, do a "clean reinstall" (remove the existing Firefox program folder, download the Firefox installer from with another browser, and then reinstall Firefox). [38] [39] [40] [41]
  • Check for profile issues by creating a new additional profile (or by creating a new default profile). If the crash issue is resolved, the simplest solution is to selectively copy your important profile data to the new profile, then reinstall your added extensions and themes. [42]
  • Problems with the page that opens when you start Firefox can cause Firefox to crash at startup. For example, if you have set as your home page, a "Google doodle" can crash Firefox (bug 773097). If you are able to start in Firefox Safe Mode, you can change your Firefox Startup setting and Home Page from the Options window General panel. If you are unable to start in Firefox Safe Mode, you can start Firefox using the -url about:blank command line argument, to open Firefox with a blank page (e.g., on Windows, enter firefox.exe -url about:blank in the Run or Start Search box). Another solution is to edit the prefs.js file and remove the user_pref lines for browser.startup.homepage and (or else reset all preferences by deleting the prefs.js file). Note that plugins can cause Firefox to crash at startup, even in Firefox Safe Mode, if your start page has content that requires a plugin and it causes a crash in Firefox (see below). [43] [44] [45]
  • If Firefox also crashes when you try to start in Firefox Safe Mode but Firefox will start when you reboot the computer in Windows Safe Mode, it's likely that other software installed on your computer that starts automatically in Windows normal mode (or malware) is causing the crash. [46] [47] [48]
  • Other software installed on your computer can cause Firefox to crash at startup, including:
    • BitGuard software (see above)
    • McAfee SiteAdvisor component of McAfee's Internet suite (see above)
    • RoboForm (see above)
    • Spector Pro for Windows (see above)
    • ThreatFire (see above)
    • Trusteer Rapport (see above)
    • ZoneAlarm ForceField, either standalone or as part of ZoneAlarm Extreme Security, if it was enabled during a Firefox update (see above for solutions).
  • Malicious software installed on your computer can cause Firefox to crash at startup. [49] [50] Even though you are running up-to-date security software, you should do a full system scan and check for malware.
  • On Mac OS, a user reports that Firefox crashes at startup if it is set to open in 32-bit mode. Right-click (context-click) on the Firefox icon, then click on"Get Info". If the box for "Open in 32-bit mode" is checked, UNcheck it, then restart Firefox. [52]
  • Crashes at startup can occur in Firefox 7 or above (but not Firefox 6 or earlier) if you are using a corporate login system such as IBM Tivoli Access Manager or Oracle Enterprise Single Sign On Manager (bug 680927). See the bug report for a suggested workaround (details here), apply the fix from Oracle (see bug comments 58-61) or downgrade to Firefox 3.6.xx (available here; however, Firefox 3.6 is no longer being maintained). Note that, starting in Firefox 10, the same bug causes Firefox to hang at startup, rather than crash, with the process running in the background consuming CPU. [53] [54] [55] [56].
  • Corrupt or duplicate fonts and missing system fonts can cause Firefox to crash at startup.

Crash when closing a tab or exiting Firefox

This can be caused by the Norton Toolbar extension included with Norton software such as Norton 360, Norton Internet Security and Norton Identity Safe. Your Norton product may have an update that resolves the issue (see this Norton community thread for current Firefox 18 compatibility updates). Otherwise, try disabling Norton Safe Search in the Norton (Toolbar) menu as a workaround. If Firefox still crashes, disable the Norton Toolbar extension in the Firefox Add-ons Manager (which you may need to do from Firefox Safe Mode) then exit Firefox completely and reopen it. [66] [67] [68] [69]

Crash when downloading

Crash when choosing a file or folder location - Windows

If Firefox crashes when attempting to select a file or folder location, such as when backing up bookmarks, browsing to a file to upload it, or choosing a location to save a file, this can occur if you have selected "Automatically expand to current folder" in your Windows Folder Options (applies to Windows 7). To resolve the problem, go to the Windows Start menu, click on "Computer" and in the window that opens, click on "Organize -> Folder and search options" and uncheck "Automatically expand to current folder" in the Folder Options "General" tab. [70] [71]

Damaged plist file - Mac OS X

On Mac OS X, sometimes a recurring crash pattern is caused by a preference file being damaged. Quit Firefox, then go to your user Library -> Preferences, find the file "org.mozilla.firefox.plist" and move it to your desktop (don't trash it; just leave it on the desktop). When you restart Firefox, a new .plist file will be generated. If the new preferences file is working well, you can trash the .plist file on the desktop. More information on corrupt .plist files can be found here. [72]

JIT compiler

Firefox Safe Mode disables the JavaScript JIT compiler ("JaegerMonkey" since Firefox 4; IonMonkey since Firefox 18; the Baseline Compiler starting in Firefox 23). If no crashes occur in Firefox Safe Mode but Firefox still crashes after disabling all extensions and turning off hardware acceleration (or if your crash reports show a JIT crash such as EnterBaseline or EnterMethodJIT in the signature), disable the JIT compiler by setting the javascript.options.baselinejit preference(s) to false in about:config (javascript.options.methodjit.* preferences in older Firefox versions). [73] [74] [75] [76] [77] [78] [79]

Video drivers

Certain video devices or display drivers can cause crashes. Make sure your drivers are up to date. Starting in Firefox 4, details about your video device and driver can be found in the Graphics section of the Troubleshooting Information (about:support) page. Note: In Firefox 4 and above, turning off the option to use hardware acceleration ("Tools -> Options -> Advanced / General -> Use hardware acceleration when available") may prevent video-related crashes. [80] [81] [82]

Hardware problems

Hardware problems, especially bad RAM chips, can cause Firefox to crash. [83] Download Memtest86 for Windows and Intel Linux or Rember for Mac to test if you have bad RAM chips.


Note: Most plugins run in a separate "plugin-container" process by default so that instead of crashing the Firefox browser, only the plugin process will crash. See Plugin-container and out-of-process plugins for more information.

Plugins are programs that work within Firefox and allow you to experience multimedia content such as video, animation or sound. Plugins can crash within their own code or can cause a crash within Firefox code. Try updating your plugins to the latest versions, which you can do through Mozilla's plugin check. You can also temporarily disable your installed plugins to see if the crashes stop, either by disabling the plugin via "Tools -> Add-ons -> Plugins" (Firefox 3 and above) or by renaming or removing the associated plugin file. See Issues related to plugins for details on troubleshooting plugin issues.

  • RealPlayer - The RealPlayer plugin may crash the browser (bug 572801) or, in Firefox 4 and above, cause a plugin crash on sites with embedded RealMedia (bug 667399). You can disable the "RealPlayer(tm) G2 LiveConnect-Enabled Plug-In (32-bit)" in the Add-ons manager Plugins list to avoid such crashes. Note: Direct links to Real Media files (such as .ram or .rm links) can still be opened in the RealPlayer application itself, even though the plugin is disabled.
  • VLC Media Player - If you are using the VLC Media Player mozilla plugin, Firefox may crash when viewing WMV media. The VLC Media Player browser plugin conflicts with the Windows Media Player plugin, so you need to disable the plugin or remove the VLC plugin file "npvlc.dll" from the Firefox installation directory plugins folder, for embedded WMV files to play properly.
  • Facebook plugin (Mac OS X) Older versions of the Facebook (Photo Uploader?) plugin "fbplugin" will cause Firefox to crash, often on browser startup, on Mac OS X 10.10 Yosemite. To resolve, remove the file fbplugin from user Library (~/Library) Internet Plug-ins folder, which is hidden by default - see Show hidden files and folders. This problem should be fixed in Firefox 34 (bug 1086977). [84]
  • Hulu Desktop (Mac OS X) - Older versions of the Hulu Desktop web plugin can cause Firefox to crash on Mac OS X. If you can open Firefox, use the Add-ons manager ("Tools -> Add-ons -> Plugins") to disable the plugin. (Note: The web plugin is listed as "Hulu Desktop Support Plugin blah -de- blah" in the Firefox Add-ons manager.) [85] To resolve, either delete or remove the "huludesktop.webplugin" file to another location (e.g., move it from the /Library/Internet Plug-ins folder to the Disabled Plug-ins folder) or else download and install the latest version of Hulu Desktop to update the plugin. [86] [87] [88] [89] [90]
  • WebEx (Mac OS X) - The WebEx plugin can cause Firefox to crash (or hang) at startup. To resolve, either delete the "WebEx.plugin" file or disable the plugin by moving it to another location. Note: The "WebEx.plugin" file is located in the ~/Library/Internet Plug-ins folder (Macintosh HD/Users/<user account>/Library/Internet Plug-Ins) instead of in the more typical root directory /Library/Internet Plug-ins folder, where other Internet plugins are installed. [91].
  • Plugins installed by malware - If you have malware installed on your system, it can include a plugin file that causes Firefox to crash. For example, on Windows, "NPFFAddOn.dll" would cause Firefox to crash at startup, resolved in Firefox 3.6 and above [92] [93] [94] See Issues related to plugins for more information on detecting and disabling installed plugins and make sure you also check for malware.

Windows compatibility mode

On Windows XP, sometimes Firefox must be run in Windows 2000 compatibility mode. Right click on your Firefox desktop icon and click on Compatibility > change the setting to Windows 2000 > click Apply.[95]

Still experiencing problems?

Crash reports

Mozilla Crash Reporter crash reports may help you locate the problem (see the linked articles for detailed information). For help analyzing the crash information, post on the Firefox Support forum with your Report ID and what steps cause Firefox to crash. Those who read your post may be able to look up your crash and find an existing bug report or file a new one for you. Also, if the crash you experience is common, it may be marked as a "topcrasher", making it more likely to be fixed in the next Firefox release.

Your operating system's system log may also have a crash report. The information will probably include the name of the module that caused the crash. On recent Windows versions, go to Start > Settings > Control Panel > Administrative Tools > Event Viewer. In the application tab, right-click on the event and select Properties. When you report the event, you should copy the information from the log.

External links