Change Your Minecraft Version or Server Type

Update to a new Minecraft version (same server type)

1. Check your plugins or mods support the new version (look on their Modrinth / Hangar / CurseForge page). Update them first, or wait.

2. Make a backup and lock it.

3. Stop the server.

4. On Startup, set Minecraft Version to the version you want, e.g. 1.21.11 or 26.1.2. latest always picks the newest version at install time.

5. Leave Build Number on latest (Paper), or Loader Version on latest (Fabric).

6. Go to Settings → Reinstall Server → Reinstall. Reinstalling downloads the new server jar. Your world, plugins and configs are kept, but the installer may replace the server jar and loader files.

   

7. Wait for the install to finish, then Start. Watch the console for plugin or mod errors.

8. Update anything that fails, then restart.

Change the Java version

The Docker Image box picks the Java version. Match it to your Minecraft version:

Choose the image, then Restart. Errors like UnsupportedClassVersionError or class file version … mean the Java version is too old.

Switch server type (e.g. vanilla → Paper, or Paper → Fabric)

The server type is the panel's egg. Changing it needs CrashCrafts staff, so contact us. Before you ask, think about what changes:

• Vanilla → Paper/Purpur: easy. Worlds carry over. Paper splits the Nether and End into world_nether and world_the_end on first start.
• Paper → Fabric/NeoForge: plugins don't work on mod loaders, so you'll need mod alternatives. Worlds carry over, but the Nether/End folders must be moved back inside world.
• Anything → a modpack: usually means a fresh server. Use Modpacks.

Memory and the start command

The default start command uses -XX:MaxRAMPercentage, so Java takes a share of your plan's memory automatically. You don't need to set -Xmx yourself, and setting it higher than your plan makes the server crash. See best practices for how much to give Java.