Glitches with the new client

This isn't a problem with my pc but my friend's client on his mac. His mac client will cause his computer to crash before loading champ select, and when trying to relog into league he can't rejoin the current game so he gets a dodge timer for something he couldn't possible stop. This gets really annoying because he has to wait 30 mins to play because it happens 1 out 5 games.