Crash signatures ^{( what's this? )}: NPSWF32.dll

If Firefox is crashing when you try to view videos on YouTube, it is usually caused by the Flash plugin conflicting with one of your extensions.

• For troubleshooting other crashes, see Firefox crashes - Troubleshoot, prevent and get help fixing crashes.

Conflict with extensions

Firefox extensions can cause this crash. To test whether your crash is happening because of an extension, try launching Firefox's Troubleshoot Firefox issues using Safe Mode: At the top of the Firefox window, click the Firefox button, go over to the Help menuOn the menu bar, click the Help menuAt the top of the Firefox window, click the Help menu and select Restart with Add-ons Disabled.... Firefox will start up with the Firefox Safe Mode dialog.

1. In the Firefox Safe Mode dialog, click Continue in Safe Mode.
2. Attempt to view videos to test for the crash.

• • If the problem does not occur in Safe Mode, an extension is likely the cause. To narrow down which extension is causing problems, see Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems.
  • If the problem still occurs in Safe Mode, follow the instructions in the next section of this article.

Flash plugin

The NPSWF32.dll file is associated with the Flash plugin. If the crash still happened in Firefox's safe mode, try uninstalling and re-installing the Flash plugin:

1. For instructions on uninstalling the Flash plugin, see Adobe.com's article on uninstalling Flash.
2. To re-install Flash, go to the Adobe Flash Player download page.
3. Click the Download now button to download the installer.
4. After you've downloaded the installer file, double-click it and then follow the on-screen instructions.
5. Restart Firefox.