I had that problem on one of my old computers. I was trying to make the reflective water, but, everything was black. There was just certain patches of land that were....invisible. When my sis got a new computer with a new graphic card, the problem went away. My advice, check your settings for the game. Mabey the settings are too high for your computer or graphic card. Or, if your willing to part ....600 dollars for a really sick graphic card, be my guest. You can buy cheaper graphic card for around 50....but, I wouldnt be able to tell you if that would fix the problem