Players stopped working. Thumbnail on iPad still not visible

With rc5 all my players stopped working.
I am using MF to play YouTube videos right now. It loads the video in the player, but nothing happens when I click the play button in the lower left or in the center of the video. I have cleared all my cache and everything seems to be up to date, with MF being the only thing I recently updated.

There is also a peculiar bug that the thumbnail image won't display on my iPad, yet it displays on my iPhone. I don't understand why that would happen. It hasn't changed on rc3, rc4, or rc5.