For a while now a friend and I have been picking at the various Halo games on Legendary coop. We’ve mostly been doing them on his Xbox One, but the entire console locks up almost every time we try to load up any Halo 4 mission. This has happened over the course of multiple weeks, and as backwards compatibility on the Xbox One is handled digitally the condition of his disc shouldn’t be the issue (the condition, by the way, being pretty good.) No other game does this to his console.
Is this an isolated incident? Or is this an issue with the majority of players?
Can’t say I’ve tried co-op on One personally, but I can make a few suggestions.
Make sure he/she has all DLC downloaded (map packs and whatever else is listed). They should be free so no need to get anything that has a price tag on it.
Check if there are any updates for the game. The back compat team occasionally releases updates for 360 games to make performance/bug fixes for the emulator.
If the game is installed on an external drive, re-install it on an internal one.
Get your friend to delete and re-download his/her profile. Make sure not to delete any games and apps. This process shouldn’t take more than like 2 minutes.
Honestly, to avoid issues entirely, I’d just play Halo 4 on Xbox 360 like it was meant to be played. It just feels better that way.