Common Questions
Java Version Errors
Fix "unsupported Java version" when starting your server
An unsupported Java version error means the Java runtime doesn't match the Minecraft version you're trying to run.
Go to Configuration → Startup and select the correct Docker Image (Java version) for your Minecraft version:
| Java version | Minecraft versions |
|---|---|
| Java 8 | 1.12 – 1.16.5 |
| Java 16 | 1.17 |
| Java 17 | 1.18 – 1.20.4 |
| Java 21 | 1.20.5 – 1.21+ |
| Java 25 | Latest snapshots and future versions |
After changing the Java version, restart your server. If the error persists, reinstall from Settings → Danger Zone.