Game freezes and I can't do anything but sign out or restart the computer

It has been happening for a long time now and I can't seem to find a fix, even in threads relating the same problem. I'm playing a game and suddenly I hear an error noise, it freezes, I can still move my mouse and when I go to CTRL+ALT+DEL to get to the task manager, the game window doesn't close so the only way to close it is to sign out or restart the computer. I've been having 20min low priority queue for months now and when it seems to be going better, it happens again. This time it just happened and when I got back into the client it just said "Game still in progress" but didn't take me to the game. I need a fix for this, I can't properly play the game and I've been doing it since Season 1. I can't even create a dump file since I can't acess Task Manager when this happens. Right now it's like this
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