My Adobe flash pluginn is crashing constantly..even my firefox and plugin is upgraded..i am not able to view any of my videos on Youtube??what i should do now?

its very frustating.even with an updated version of firefox browser beta 26 and shockwave pugin,it still crashes...i have windows 8 pro operating system.... plz suggest a solution for the problem.......fast.. yesterday i upgraded my mozilla firefox browser to beta 26..it was playing videos and today when i am trying to view them..it is showing crashed shockwave plugin.... what am i to do now??