I have C:MO through Steam, along with a couple of DLCs. I have not played in a while and tried to start it up the other day.
The game starts fine from the launch screen, however there is no map visible. The UI is complete, but there is no world or units visible. Pop-up messages appear as usual, but the central part of the display is simply white. I have tried updating graphics card drivers and windows updates, but no joy. This has never been an issue previously.
I am running an older PC with windows 8.1, but have DX11, and have not had issues with the game in the past.
Any suggestions would be appreciated. I have uninstalled and reinstalled several times, and verified game cache successfully. I am banging my head against the wall.

Thanks for any tips!
Cheers,
ColDawg