Recent crashes of certain multimedia contents (this includes Youtube videos, certain flash games and other applications) in conjunction with Firefox 13 are most probably caused by a recent Flash 11.3 update and/or a malfunctioning Real Player browser plugin.

In order to remedy the problem, please perform the steps mentioned in these Knowledge Base articles:

Flash Plugin - Keep it up to date and troubleshoot problems

Adobe Flash plugin has crashed - Prevent it from happening again

Flash 11.3 doesn't load video in Firefox

Other, more technical information about these issues can be found under these Links:

http://forums.adobe.com/thread/1018071?tstart=0

http://blogs.adobe.com/asset/2012/06/inside-flash-player-protected-mode-for-firefox.html

Please tell us if this helped!

Your system details show you have RealPlayer installed, which includes the Real Player Browser Record Plugin extension that is not compatible with Firefox and the latest Flash 11.3 plugin.

See the following for more information:

• http://kb.mozillazine.org/RealPlayer#RealPlayer_Browser_Record_Plugin_extension

Don't worry Simply uninstall Real Player and any extension of RP from computer and Firefox. It will definitely working. I have same problem but solved after uninstalling Real Player.