Tom Dodge

I am playing the campaign on easy and when I finish mission 4 it goes through the cut scene and than back to the main screen to start mission 4 again. I was playing from the disk. I installed the game and played mission 4 again and the same thing happened. I than uninstalled the game and reinstalled it, played mission 4 again and it happened again. So now I can't go any further in the game on campaign. Is there a fix for this? I have searched the forum and I am unable to find a solution?