[CLIENT] Game doesn't load after champion selection phase.

Everything goes well till I select my champion. Countdown hits 0 and the game launches but instead of the usual loading screen I'm stuck at a black screen. It's been like this since the last 7 days, I've repaired the client when it was 5.9 and then even updated to 5.10 when it came. Nothing has worked.

I'm on the Mac Client of League.

iMac (27-inch, Mid 2011) Processor - 3.1 GHz Intel Core i5 Memory - 12 GB 1333 MHz DDR3 Graphics - AMD Radeon HD 6970M 1024mb

Regards, DivineRicardo