Opening a Chest crashes my game.

So I won a game of Aram where I got a S- on my Mastery 5 Akali (Shame that I didn't get a token as well but its ARAM Soooo) Anyways, I was trying to open the chest and I couldn't open the Chest. I tried clicking again and the game just outright crashed. I Launched the client again and just right clicked on it but it crashed again. Is there any reason why this happens? RIto Pls