Outdated client or outdated server: matching versions
The client and server are on different Minecraft versions. Bring the client in line, or change the server version from the dashboard.
An Outdated client or Outdated server message in the Minecraft connect screen means the version of the client trying to join does not match the version the server is running. The fix is to bring one of them in line with the other; almost always, the client.
Reading the message
Outdated client means your client is older than the server's version. Update the launcher profile to the version the server is on, or ask the server owner to downgrade.
Outdated server means your client is newer than the server's version. Pick an older version in the launcher, or the owner needs to upgrade the server.
If you own the server
Open Dashboard → your server → Settings → Game version. Pick the version your players are on, save, and restart. A downgrade prompts a warning because chunks written on a newer version do not open cleanly on an older one; back up first (Taking a manual backup) before downgrading.
If you are joining someone else's server
Open the Minecraft launcher → Installations → New installation → pick the version field and choose the exact version the server runs. Use that installation to launch the game, and the message clears.
Modded servers
Forge, Fabric, and NeoForge servers pin the Minecraft version to whatever the pack uses. Joining an ATM10 server with a vanilla 1.21.5 launcher will fail; you need the matching loader and the pack installed. The pack's CurseForge or Modrinth page lists the exact loader version.
Cross-version proxies
If you specifically want players on different Minecraft versions to connect to the same server, the answer is a proxy in front of the server with ViaVersion loaded. That is a per-server choice and not enabled by default; see Hostd Linkd: connect multiple servers into one network for the bigger picture.
Where to go next
- Changing the Minecraft version if you need to flip the server version.
- Connecting to a Minecraft Java server once both ends are on the same version.
Last updated 2026-05-23. Notice a mistake? Tell us.