Error code: CO4TOOR17X-01 50617274079B

When trying to connect with a friend who has exactly the same version of AOE 4, we keep getting the following error message:

The match you’re trying to join is running a different version of the game. If you are already up to date, then the players in this match also need to update their games.

If you need to update your game, please quit, download the update, and re-launch it.

If this problem persists, please visit http:// ageofempires.com for support.

Error code: CO4TOOR17X-01 50617274079B