Mac crash with many odd circumstances

Hello,

I recently experienced an odd crash/bug. I am on an iMac, with an additional screen attached. When I started up the match, one screen was the primary screen so LOL launched on that one. I changed the primary screen to the larger resolution monitor, and LOL appeared with a black frame, with the loading screen the size of the smaller resolution monitor. When I quit and restart league, I was unable to reconnect to the game and continuously received network errors UNTIL the game started, when I was allowed in. Any idea what could have caused this?

Thank you,

Amerod