Vibrating screen
lol_bugs
I upgraded to the latest version of MAC OSX (El Capitan) and when running connected to my external monitors, one, the one that is not running league, does a very annoying flash/flickering/right clicking/alt tabbing, essentially what I was doing prior to the game loading.
It is very distracting.
I'm linking to a video to demonstrate. Link will expire at end of 2015.