I am the creator of the C&C Tiberian Dawn/Red Alert Redux Mod and the Realistic Weapon Mod for C&C Generals Zero Hour. You might also know me for pioneering a release of a Generals/Zero Hour Mod with enhanced revolutionary graphics! I have also been an assistant programmer and map designer for Vietnam Glory Obscured.
It has been brought to my attention some popular third party software for the game or using custom video resolutions can cause issues with a "black bar" rendering in-game. A workaround is to use the modified GameData.ini with DrawEntireTerrain enabled. It goes in the games Data/INI folder.