On Mac - After champion select, black screen.

I will enter a gamemode of any type (including customs), get past champion select. Then the new client opens up and I get a black screen on it that does not go away. I play on mac os x high sierra and have not ever had this issue before. (playing for 4 years) But ever since I've first gotten this, I have not been able to load up a single game. I do not get any crash reports after I close the program and am not sure what to do.