I just bought this game a few days ago and i've received constant crashes over the course of my gamplay, most times I cannot play longer than 1 full mission. From the crash reports, a majority are Unhandled Exception: EXCEPTION_ACCESS_VIOLATION. I've also gotten an Unhandled Exception: EXCEPTION_PRIV_INSTRUCTION error and also:

LowLevelFatalError [File:Unknown] [Line: 198]
Unreal Engine is exiting due to D3D device being lost. (Error: 0x887A0006 - HUNG)

I have the full vanilla game with all DLC's installed and no mods. My system is well above the minimum specs. I've re-installed my graphics driver, adjusted the GPU clock speed to normal (my GPU is pre-OC'd by the manufacturer), changed the graphics settings in-game and verified the MW5 files through GOG Galaxy. No dice, same errors. From my searches on Google, it seems to be a common software-related issue with UE4 games, not just MW5. Has anybody else had this problem? Are there any work arounds? Any/all help would be hugely appreciated.

I tried all that, thank you.

I did manage to figure it out though. The GPU would overheat at +80'C and UE4 would CTD as a result. After improving the case airflow and reapplying thermal paste to the GPU heatsink (it's a 4yr old old GTX 10 series card), I was able to lower temps by 10'C and i've had game stability and no issues since.