Screen going black after Champion Select

Hi Im running a mac OS X Yosemite 10.10.1 and the moment since Rek'Sai was release my screen would go black right after the champion select until it game me the "cannot connect to the PVP.net sever." I've looks over the trouble shotting and have tried just about every thing from resetting route, restarting computer, restarting LoL, looking for logitech files and delteing, the keychain access fix, and random button mashing and pressing enter 5sec after black screen. Nothing seems to work. I've also had this problem in the past and changing my wifi from WPA/WPA 2 to a WEP worked, and vice versa. I've tried that here and it seemed to work a couple times (as well as waiting a few hours and changing routers) and got it to work a couple times in custom game. So I went to go join a normal (which took 20min just to join q cause of my "leaver buster," it did the same black screen problem.