Can't watch YouTube.

[Flask]

Hi All
I am on a mac book air. Mountain Lion.
All was fine, then a while back, I was unable to watch youtube on FireFox, and Chrome.
Still can not.
Safari works fine, if I am using Chrome, and want to view a youtube video, I have to copy and paste the link into Safari.
Any ideas on what went wrong would be greatly appreciated.
Thanks

 

[justperry]

Reset both Applications, such as removing cache, cookies history and so on, if this does not work you should look in your preferences Folder, there are .plist files there which you could delete.

Most likely those are named "com.chrome.plist" and "com.firefox.plist".