Steam / Win10 64-bit NVidia gfx latest drivers.

EDIT:  I thought this might be a hardware cooling issue but now believe it's the game, since it happens at the same exact point repeatedly.

It should be easy for someone else to test this...

Set up a skirmish between two "Insane" AIs on the Espana map.  Turn Victory Points, neutral creeps, air units, and orbitals off.  Zoom all the way out, and run the match at "Fastest" speed.  It takes about 10 minutes for the first nexus to be destroyed.  Click on "keep playing".  Shortly thereafter, and usually coincident with the second nexus falling, the game locks up on my PC.