Yea im having the same problem. First it was when i logged on there was just a blank screen with the blue outline of the launcher. I re installed and now its fine. But then when i wanted to play a ranked game, after champion select and game countdown to 0, only a black screen appeared and nothing else happened for the next 5 minutes.... there was no loading screen, just black....

You said it's "resolved" but i dont see anything which helps me solve this problem..
@RiotRara
Could u please just tell me a step by step way to solve this issue as it is getting quite annoying.
This issue happened ever since the Shyvana Patch...

!? no response still? HELP!

This may help depending on the issue that you are experiencing.

Nvidia Control Panel > Advanced > Manage 3D settings
> Anisotropic filtering = Application controlled
> Antialiasing - Setting = Application controlled
> Vertical sync = Force on

but i am using macbookpro with vmware using window 7

Still. Not. Resolved.