League of Legends client stops working at random rates!

League of Legends client stops working at random rates! Ill get those when 1. opening Hextech crafting slot in main menu 2. when going to the new Draft pick 3. banning a champion at Draft pick. And it only happens sometimes! How it crashes? Client freezes and texts are shown at random places. Then you have to shut down the client and log in again to fix it! Its happening me often when I ban a champion in Draft pick. Then I get those 5 min bans for leaving champion select. Its kinda annoying and stupid! Riot fix it!