My server crashes or won't start
When a server stops during startup, the reason is almost always printed in the console just before it stops.
1. Read the console
- Open the Console and click Start.
- Watch until it stops. Scroll up to the first error - later errors are usually knock-on effects.
- Look for lines containing
ERROR,Exception,Caused byorFATAL.
For Minecraft, crash reports are also saved in the crash-reports/ folder.
2. Match the error
| You see | What it means | Fix |
|---|---|---|
OutOfMemoryError / server killed with no error | Ran out of RAM | Remove heavy mods/plugins or upgrade your plan |
Failed to bind to port / Address already in use | Port changed or already in use | Don't set server-port manually - see server.properties |
Unsupported class file major version / UnsupportedClassVersionError | Wrong Java version for this Minecraft version | Change the Docker Image on the Startup tab to a newer Java |
Could not load 'plugins/X.jar' | A plugin is broken or for another version | Remove or update that plugin |
Mod X requires Y / missing dependencies | A mod needs another mod | Install the dependency, matching versions |
Unable to access jarfile | The server jar is missing or misnamed | Reinstall from Settings → Reinstall Server |
Exception in server tick loop | Usually a corrupted chunk, entity or mod bug | Restore a backup, or remove the last mod added |
3. Undo the last change
If it worked yesterday, whatever changed since is the prime suspect:
- New plugin or mod? Move it out of
plugins/ormods/and try again. - Updated the version? Restore the backup you took before updating.
- Edited a config? Check it for typos - a missing quote or wrong indentation in a
.ymlfile stops some plugins loading.
4. Find a bad mod or plugin quickly
- Move half of your plugins/mods into a temporary folder.
- Start the server.
- If it starts, the problem is in the half you removed; if not, it's in the half that's left.
- Repeat with the problem half until one remains.
Server shows "Suspended"?
That's a billing state, not a crash - see My server is suspended.
Still stuck? Open a ticket on Discord - run /ticket in any channel, pick a department, and include your Server ID or Invoice ID so we can jump straight in.