Where are you trying to move it too?
Can you click on the link below for me please? You'll see a large white page with the text in the corner saying 'chess.com cookies cleared'. Once you see that, close the browser then re-open it and log back in
http://www.chess.com/clear_cookies.html
On move 30 in http://www.chess.com/echess/game.html?id=49289262, I cannot move my Bishop