How to Fix Flash Player if not Working in Youtube

There are times that flash in Firefox and in Chrome is not working with Youtube and it only shows a grey screen in the place where the video should be, but it is working fine with other video sites like facebook.com and  with Adobe's Flash player test.

To fix this problem, we need to Disable the hardware acceleration. 

By default, Enable Hardware Acceleration is selected to improve the quality of playback in Flash Player, particularly the performance of full-screen playback.

 

If you have display problems with Flash Player, such as poor picture quality or slow display times, deselect Enable Hardware Acceleration in the Display panel. This should eliminate hardware or driver compatibility problems with Flash Player. Flash Player then uses software to scale and display the content.

This is how to disable hardware acceleration.

• Click the troubleshoot and reporting flash player video issues.
• Right-click (Windows) or Control-click (Macintosh) the application image during playback.          
• From the context menu, select Settings and unchecked the display hardware acceleration.

I hope that it helps and please beware of disabling any security features in our browser that leads it to be vulnerable from any kind of malware.