Hella there Guys!
My Problem is that i cant Start Halo:Nightfall,i Open up the Game,go to the Extras menu and open up Halo:Nightfall,iam connected to the Halo Channel and the Nightfall screen,but i cant Start it,there is only a Button saying You Need to buy Halo to view Nightfall! I press the button,i will be transfered to the Game and directly to the extra screen with the Halo:Nightfall Video Option,but if i press it i go back to Halo Channel and Nothing has changed,still i cant Start the Episode because there is only the: You Need to buy the Game button! if i press it again everything Starts over but it wont change! I Hope my englisch wasnt too chaotic im from Austria,so sry if someone feels hurt inside himself because of that 
thank for the replies and hopefully a Solution