Forum Response - Flash 11.3
Recent crashes of certain multimedia contents (this includes Youtube videos, certain flash games and other applications) in conjunction with Firefox 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:
Other, more technical information about these issues can be found under these Links:
Please tell us if this helped!