[CLIENT] loading screen freezes at 54% preventing me from playing the game!

This happened 4 times now while trying to play ARAM. When i get in the loading screen after we all picked our champs, the loading bar freezes at 54% making me un-able to join the game, while others already did!

And when i restart the client hoping to fix the problem, it freezes at 4% instead.

Funny how this shit only happens when i got a single task left to complete a mission, but now i'm afraid of playing in other gamemodes only to get this problem and find myself infront of a 20min Ban...

Rito, plz fix.