Black screen

Okay so this has happened to me 2 times in a row now but I went into champion select for a ranked game and when I get there the screen goes black and I cant pick or ban but I can see my back ground and I can open the options on the top right and see it. Is this a bug or do I need to reinstall or whats the deal with this ? I currently have a 30minute ban since I cant ban or pick a champ i timed out.