What were you doing at the time? Has it crashed before? Other issues?

The crash report flagged;

igd10umd32.dll = Intel(R) Graphics Technology

If you have problems with current Shockwave Flash plugin versions then check this:

• see if there are updates for your graphics drive drivers

https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

• disable protected mode in the Flash plugin (Flash 11.3+ on Windows Vista and later)

https://forums.adobe.com/message/4468493#TemporaryWorkaround

• disable hardware acceleration in the Flash plugin

https://forums.adobe.com/thread/891337 See also:

• http://kb.mozillazine.org/Flash#Troubleshooting

Your crash report is linked to two page in the bug tracking system, where similar crashes were traced to two specific programs:

• old versions of Comodo Internet Security (version 5.12 and below)
• nProtect GameGuard (http://en.wikipedia.org/wiki/NProtect_GameGuard)

There certainly could be other causes, but could you investigate whether you might have either of those?

A similar but slightly different crash signature showed up in this thread: Firefox crashes after I open a new tab.

Will Firefox start in its Safe Mode?

If Firefox is not running: Hold down the Shift key when starting Firefox.

A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any less crashy?