Leauge wont open, Show's "Leauge of Legends" and then does nothing

its your computer not league check fi youre not running too much stuff at the same time

Open Task Manager and see if there is a background lolclient.exe or something similar that might be bugging, usually it's the kernal. Kill it and try again.

So I don't know why this worked for me, but here's my story: I had LOL installed about a year ago and deleted it to make hard drive space. Then I Decided I wanted to play again, so I checked and MADE SURE all of my files were deleted on my MAC. I went to the website, ReDownloaded LOL fresh from the website, tried installing it and it wouldnt open from my applications folder. It would open the small "league of legends" ICON in the center of the screen, however, it wouldn't load the launcher. Fortunately for me, I have a external hard drive (LaCie) so instead of moving the LoL file to the applications folder, I moved it to my LaCie hard drive, double clicked it from there, and BOOM. No problems, LoL opened perfectly, no issues what so ever. I hope this helps you guys but this is how I fixed this issue. :)