Error code

Minecraft Outdated client

MINECRAFTOutdated client
Game/Platform Error· An error code shown by a game or gaming platform/launcher.

What it means

The server rejected you because your game version is older than the server's version.

How to fix it

  1. Open the launcher and go to Installations.
  2. create or select an installation matching the server version.
  3. check the server's required version in the multiplayer menu.
  4. launch on that version and reconnect.

Not affiliated with Minecraft. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.