Start game with Yasuo [CRASH]

When i want to play Yasuo , when we first saw the summoner rift and the champions aren't spawn yet. The game froze (interface) but not the sound. It's look like the game is never spawning champion or anything. When i try to go on my desktop all other application and LoL doesnt response anymore. I can't also lauch my ctrl + Alt +Del for the task manager. I can only restart my computer to solve the current problem. After i relog into LoL ,i can easily reconnect to the game without any problem. Sry bad english : P