This is a known issue with Unreal Engine and not a problem with the game in particular. It's being worked on but affects a TON of players, including myself.
https://issues.unrealengine.com/issue/UE-42280
https://answers.unrealengine.com/questions/545292/unreal-engine-is-exiting-due-to-d3d-device-being-l-3.html