Mostly because you didn't say what operating system you're using or which browser...
We need that before we can do more than guess.
Using firefox and adobe system 11.8.800.94
Is your pc. laptop, whatever Windows -ana what version, like Windows Vista, or Windows 10.
What bit is it? 32 or 64?
You can get that info by right clicking on "My Computer" Uusually on the desktop) and selecting Properties in the drop down menu.
And what version of Fire Fox are you using?
And which plugin are you using, and is it for Flash Player?
This info will help someone to answer your question.