If Adobe Flash Player is crashing on you (especially in Firefox), be aware that a recent update to Flash Player 11.3 is causing widespread problems. Adobe has released a new version of Flash player that is supposed to fix it.
Adobe fixes Flash Player for Firefox to stop crashes
I downgraded to 11.2 a couple days ago, and it's appears to have relieved the problem.I think I'll just wait for the next update now.
To test your flash player, play the following video (Courtesy of Theo's) repeatedly. If it doesn't crash within ten plays, you're probably fine...