This is a major mac related bug I do believe, I too get black screen/white screened as well as bug splat at the same time. Also since the patch I get a firewall message asking if you want League to receive incoming connections. Despite having League pardoned in the firewall, the message continues to pop up every single game I try to start. The same bug exists in PBE too, basically we cannot play the game until the bug is patched. Just for further reference this bug happened over a year ago as well and prevented mac users from playing the game at all. All other games outside of League work fine so this is a major mac related bug although I am hearing there are a few windows users being affected. A response from the team would be great instead of keeping this bug on the hush hush until next patch.