I can't access videos on youtube any more. The page opens as it should and I can see all the video information and all comments and video suggestions, but the player itself is only a black screen. There are no controls and no picture. I can still watch the videos embedded on other sites or in email, but not directly on youtube. It's definitely a Firefox-related issue, because I double-checked with IE and everything worked fine with those browsers. I tried the solutions in this page https://support.mozilla.com/hy-AM/questions/763673 I used CCleaner, but still no help.. It was working fine few days ago.. I have no idea what happened. Please HELP!