Is this a persistant problem that happens in every game or was it just this game. What happens when you start a 1:1 bot game? Are you able to load the game? If you are still having problems, please share your lolclient and r3dlog and I will take a look.
@Axxed The launch screen is independent of the queue type. It doesn't matter all what queue you are in. It appears that there is a problem with your graphics card or lol installation or there is a network issue.
1) sharing your logs
2) updating your drivers if they are old.
3) repair or reinstall the client.
@Varghulf: At my feet.