Can't get into Loadingscreen Macbook help someone!

When i get to champion select everything is fine, but when it goes to loading screen she screen just goes black and won't work. I then read it would help to press enter, and i does i can see the loading screen for about 0.5 seconds, then i just closes and pop up with: "League Of Legends quit unexpectedly"

Pls help someone i can't seem to solve it!