I don't know who else has this problem, but many of my friends do to. After the Rockstar logos when I first start my game I get an all black screen for about 10-30 seconds. We all run the game as admin and we have a stable modpack. After we wait for the 10-30 seconds to pass by the everything works fine. I have a lowish end computer, but I can play at 1360x768 and medium texture quality with 30+ frames. I have tried re-installing my game along with my friends several times! Any help is greatly appreciated!