Minecraft Outdated Server or Outdated Client? How to Fix It

"Outdated server" and "Outdated client" in Minecraft mean your game and the server are on different versions. Minecraft only lets you join a server running the exact same version as your game, so the fix is to match them: either play the server's version from the launcher, or update the server to the version everyone plays. This guide shows both, plus what to do on modded servers and after a big update.

What the error says

When you try to join, you see Failed to connect to the server followed by one of these:

Outdated server! I'm still on 26.2

Outdated client! Please use 26.3

Incompatible client! Please use 26.3

The version in the message is the useful part:

In the multiplayer list, a server on another version also shows a red cross or the text "Incompatible version" instead of the ping bars.

Short answer

Open the Minecraft Launcher, click Installations, then New installation, pick the version the error message names, save it and press Play on it. Then join the server again. If most of your group is on a newer version, update the server instead.

Fix 1: Play the server's version (players)

The launcher can run any release of Minecraft: Java Edition side by side.

1. Open the Minecraft Launcher and pick Minecraft: Java Edition.
2. Click the Installations tab.
3. Click New installation.
4. Give it a name, open the Version list and pick the version the server runs, for example release 26.2.
5. Click Create, then hover over the new installation and click Play.

Now join the server. If you cannot find the version, tick Releases at the top of the Installations tab, and Snapshots only if the server runs a snapshot. Your singleplayer worlds are not touched, but do not open a newer world in an older version, since that can break it.

If you play through a modpack launcher such as CurseForge or Prism, change the version in that profile instead, or install the pack version the server runs.

Fix 2: Update the server (owners)

When a new Minecraft version comes out, the launcher updates everyone to it automatically, so the day after an update most "Outdated server" errors come from the server being behind.

• Vanilla: download the new server jar from minecraft.net and replace the old one.
• Paper: download the build for the new version from papermc.io. Paper often needs a few days after a release to catch up, and plugins may need updates too.
• Hosted on GamezServers: pick the new version in the panel. Click Backup first.

Before updating, remember:

• Back up the world. Updating is one way: once a world loads on a newer version, older versions cannot load it safely.
• Check your Java. Minecraft 26.1 and newer need Java 25. Older Java stops the server with UnsupportedClassVersionError.
• Check your plugins or mods. A plugin built for the previous version can fail to load or break the server until its author updates it.

Fix 3: Let several versions join

If your group cannot agree on one version, Paper servers can run ViaVersion, a plugin that lets newer clients join an older server. Its add-ons ViaBackwards and ViaRewind let older clients join a newer server. New blocks and items do not appear for players on older versions, so treat it as a convenience, not a full fix. ViaVersion is a plugin, so it works on Paper, Purpur and similar servers, not on vanilla or Fabric.

Modded servers: the version is not just Minecraft

On a Forge, NeoForge or Fabric server, you need the same Minecraft version and the same mod loader and the same mods. Errors on modded servers look different but have the same root cause:

• "Mismatched mod channel list" or "Missing mods": your mods differ from the server's. Install the exact modpack version the server runs.
• "Incompatible FML modded server": you joined a Forge server with a vanilla or Fabric client. Launch the pack's profile instead.
• Stuck on "Loading terrain" or kicked right away: one mod version differs. Compare the mods folders.

The easiest fix is to run a modpack from CurseForge or Modrinth, so everyone installs the same pack version in one click. Our guide to installing mods on a Minecraft server covers keeping client and server in sync.

Bedrock players

A Bedrock player (console, phone, Windows Bedrock) cannot join a Java server at all unless the owner installs Geyser and Floodgate. With Geyser, Bedrock players join on its own port and Geyser handles the version gap, but it has to be updated after Bedrock updates.

After every big update: a quick plan

1. Tell your group not to update yet, or to keep an installation of the old version.
2. Wait until Paper and your key plugins or mods support the new version.
3. Back up, update the server, start it and check the console for errors.
4. Everyone updates and joins.

The easy way

Keeping a server in step with Minecraft updates means downloading jars, checking Java versions and backing up by hand. On a hosted server you pick the version in the panel, back up with one click, and switch back if it goes wrong. See Minecraft server hosting or the quick start guide.

FAQ

How do I check what version a Minecraft server runs?

The error message tells you. The multiplayer list also shows it when you hover over the red cross. On Paper, the owner can type version in the console, and the version is printed near the top of the console on every start.

Can I join a newer server with an older Minecraft?

Not without ViaBackwards on the server. Otherwise you need to update your game to the server's version.

Why did it work yesterday?

The launcher updated your game to a new release overnight, and the server did not update yet. Play the older version from Installations, or ask the owner to update.

Will downgrading my server delete my world?

It can corrupt it. Older versions do not understand newer blocks and data. Restore a backup made before the upgrade instead of downgrading a world.