The "hit box" on the minimap is black

A little picture is better to explain :



I’m encountering frequent crashes with the campaign expansion, usually right after I win a battle. This means I have to repeat a lot of battles, since it doesn’t save the game first. The main game (without campaign) doesn’t crash like this.
All running inside of a virtual machine guest with a Windows OS host…

I’m getting dozens of pop-up shader errors but the battle plays through.