Sun Oct 21, 2018 4:25 pm by bob
Well, current Dev is 6331, not 6319, so maybe you have some more patching to go?
And no, the Win8 fixes were due to Windows API's that had diverged.
With 8.1, AFAWK it should all be working. Your Windows is fully patched?
The compatibility diagnostic, if you don't want to share it, you should be looking for other things hooking into the game process that aren't necessary for the game, and shutting them down. If there isn't anything there, then other overlays, antivirus, screen grabbers and such programs.
Also, you didn't confirm/deny if we are talking older versions of the game. There are some older versions which just have this error. Fixing those usually requires some good luck that it gets picked up with something else that has the issue on release.