My friend is stuck on this mission called "madd dogg" I think it's one of the heist mission. What happens is when he walks into the marker out front of the casino it goes to the cut scene. After the cut scene is finished your suposed to get a car and save madd dogg so he can jump in the back. Instead madd dogg just jumps straight after the cut scene and dies which fails the mission. This is pretty much an imposible mission.