NIGHTFALL'S PROBLEMS

Ok so whenever I go to halo nightfall on my Xbox I try to buy it then it asks “You need an app to install this task” so I press ok. Then it takes me to a blank screen that says sorry we couldn’t find that app and the search thing was marketplace and then I search marketplace in my search bar and 2 things pop up and I install both of them and then I go back to nightfall then it asks AGAIN you need an app to install this task so I have All halos ALL OF THEM on my xbox (except reach) so whats going on 343 industries I want night fall odst armor so bad. Can you just send me a req pack or something like that Please. Video for proof The nightfall problem - YouTube <---- copy and paste that link