I also kept getting a bug splat on entering the loading screen very consistently for multiple games in a row (I play custom game summoners rift with no bots and only me). Finally, I decided to delete the game.cfg and the input from the Config folder. After doing this, I was able to get into the game! While ingame, I decided to change my video/sound/keybinding settings and exited the game right away to start a new one. Got another bug splat starting the new game Deleted the game.cfg and input again, started a new game successfully, DIDN'T change game settings, exited and started ANOTHER new game, and was able to do so successfully ... so, it seems to me that it crashes if you have some custom video/sound/keybinding set to load on start of the game. I hope this information helps.
EDIT: Attached game.cfg and input that were in use during the crashes.
EDIT2: Also attaching dxdiag