Ok, so 2 days ago i reformatted my comp, started over from nothing, re downloaded league of legends, and ever since i downloaded the patch, my client has been closing MID GAME, it will get a bug splat or just randomly close, whats going on? its ruined alot of my games, got me raged at, reported, and its ruined my gaming experience.
Can anyone answer this for me

Are your drivers up to date?

Hit ctrl + alt + delete and click on the processes tab. Could there be anything there that might be conflicting with LoL?

Also what Encased said. Out of date drivers can very well be causing the problem.