Game crashes 2 times! when i have new client open at background wtf ?!

During a ranked game my game crashed too desktop 2 times saying league of legends doenst respond. It happend when someone sended a message to me in chat through the client :( This is so bad! Can u plz fix this ? Pc specs: Intel i5 7600k Radeon r9 380 gaming 8g ddr4 Asrock 250m pro 4