Alt tab/Alt enter crashes

[Slayer]

Hi, I've been having some recent issues that i've never experienced before, when I alt tab out of the game now, I always crash, its not a 50/50 chance it is always. Previously I would never have this issue, it is only recent.

The same happens when i hit alt+enter to make the game windowed, I simply crash.

Could this be an issue with my specs or something? I have no idea, any help would be greatly appreciated, thanks!