Startup Issues, Black Rectangle when opening

I just updated my game, logged in and then exited out. Now whenever I opening league it has the first League of Legends Icon and then nothing. I then go to open it again and all I get is a black rectangle where the game should be. If i close it (using the task manager) and try again I get the same thing, having to open it twice and then getting the black rectangle. I tried uninstalling the game and then reinstalling and from the first boot up of the new install it has the same thing.

UPDATE I restarted my computer and it is now working.