Ok guys after countless hours Iv fixed my halo nightfall I can now watch it.
to yous that can’t because it just stops playing do this…
1 start up halo channel
2 back out and go to apps click halo channel and manage it
3 uninstall halo nightfall add on
4 return to the halo channel and click play on nightfall.
Notes it’s a little glitchy so pause for a min to let it buffer
Didn’t work 
Doesn’t even show any add-ons for me.