I installed the game. Checked video settings before running, changed nothing but looked at all the options...noticed I could choose DX9 or DX11, left it on 11. Ran it once fine. Played a few tutorial scenarios. Had to quit for a few hours. Came back and tried to start it up, intending to start my first real game. Immediate crash to desktop with a DX9 error message. Go back to the options, and it is set to DX9 - went to change it and DX11 is no longer available to choose. I uninstalled and reinstalled twice now, still no DX11 to choose from. Manually updated my DX11 drivers, still no DX11 to choose from. What is going on?