Halo Nightfall Not Working

When I try to watch Halo Nightfall on the Halo Channel, it continues to tell me to “Buy Halo”, although I already own the Master Chief Collection.
I purchased the MCC on the Xbox One digital store, and every time I press “Buy Halo”, it returns me to the game, and when I press watch Halo Night fall on the Master Chief Collection, it just sends me back to the same place on the Halo Channel where it tells me to “But Halo”
I tried uninstalling, re installing the Halo Channel and Halo Nightfall. Completely turning off the Xbox One and unplugging, then re plugging the cord back in.
I’m lost, and I really want to watch Halo Nightfall, does anyone know what to do and how to fix it?

You have to enter the code you got with the game for Nightfall.

Your Suppose to Enter the Code, you got within your box. the download after you enter the code should be called “Nightfall and Halo Channel Bundle”
After that click enter, and in a couple Minutes you should have access to Halo Nightfalls First episode.