To fix the Dev Error 11557 in Modern Warfare 2 and Warzone 2.0 follow the suggestions laid done in this post. They have helped many!

The devs noted a fix for an issue “causing some Players to encounter Dev Errors in Building 21”.

To fix Dev Error 5523 on CoD, MW and Warzone scan the game files and disable Overlay and update the graphics drivers. If that doesn't help, follow these suggestions.

And that’s how to fix the MW3 Dev Error 5433. If you need help with other Call of Duty issues, here’s a guide on what the loadout glitch is in Warzone and how to fix it.

Unfortunately, at the time of writing, Activision hasn’t released a full fix yet. Call of Duty: Modern Warfare 3 and Warzone are available on PC, PlayStation, and Xbox.