The latest Call of Duty Modern Warfare 2 and Warzone 2 update is now available! However, some players are experiencing logging or connection error 2004.
This error is very common when you launch games in multiplayer mode. Unfortunately, there is no solid solution but we’ll give you some workarounds.
First, check the game servers, they may be offline. If this is not the case then, the problem is certainly with your internet connection, so you can try the following steps:
Restart your internet connection.
Restart your Computer
Try another internet connection to connect to the game. You can use your phone's connection for example.
If all these methods are ineffective, then we advise that you report this to the official Activision website.