100% Loading Screen

Haven't played League in like 5 Months, so I wanted to play some random Botgames today but for some weird reason my whole Game just freezes when the Loading Screen reaches 100%? The game doesn't start and I'm not even able to ALT+TAB out of it so the only thing I can do is completly turn my Laptop off since nothing works anymore (not even Taskmanager etc.)

Any Ideas?