finally got the game to work as i had to set the nvidia graphics card as my default card for all programs as for some reason selecting a game individually and setting the graphics card did not work, as said game is now working.

I've tried re-installing the game and i have tried verifying the game cache, drivers are upto date, but I still can not get game to work properly screen still black, I've read the steam forums and have noticed a couple of people have the same problem as me, the graphics card i'm running is NVIDIA ...

the patch version release candidate 1 build 1502 just downloaded and i can not play sovereignty anymore as the game loads and i go to select new game and the campaign map is black the only things that are visable are the names of realms and when i select a realm and game loads up the map is black ...