I can't play two profiles multi-player on my Xbox One anymore

Before you open the game, go to network settings and put the console in offline mode, then open mw and go into offline mode there aswell, it should let you add player 2 and you can make custom matches, you can make ur console online again after you add player two, sadly you can only play against bots but atleast its a start.

As mentioned here

https://www.reddit.com/r/modernwarfare/comments...

What do you mean by what mode?

You can play the spec-ops or multiplayer game modes in local two-player split-screen. You are unable to play Call of Duty: Modern Warfare's campaign in split-screen, or play with more than two people on one screen.

The spec-ops game mode, often known as the co-op game mode, can be played in two-player local split screen without limitations. The multiplayer split-screen applies some limits on what multiplayer game modes can be played. Common game modes like Team Deathmatch or Domination are available, but alternate game modes such as Infected or Free for All are prohibited as having two players working together may provide an unfair advantage.

You can also play local multiplayer called "private matches" which pits you and your ally against each other or against bots using maps and difficulties you select. These private matches do not allot any XP to your multiplayer characters but are heavily customizable and can be played offline in split-screen.

As mentioned here

https://gaming.stackexchange.com/questions/3600...

Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.

I understand, but as I mentioned not all game modes allow you to play in split screen, that would be 2 controllers as you said, what mode are your trying to play on split screen?

I'm just trying to play the normal Call of Duty Modern Warfare multi-player with 2 controllers on one console