Troubleshooting Your Minecraft Server

Here are common Minecraft server issues and how to fix them.

”Failed to verify username!” or “Authentication servers are currently not available”

This error occurs when your server cannot connect to Mojang’s authentication servers. This is a permanent issue for Minecraft versions 1.16.5 and older due to changes in Mojang’s TLS certificate that are incompatible with Java 8.

For Versions 1.16.5 and Older

If you’re running Minecraft 1.16.5 or earlier, you have two options:

Option 1: Update to a newer version (Recommended)

• Update your server to version 1.17 or newer
• Versions 1.17+ use Java 17 which supports the modern TLS certificates

Option 2: Enable offline mode

• Enable offline mode to bypass authentication
• Note: This allows anyone to join without account verification
• Use an authentication plugin for security

For Versions 1.17 and Newer

If you’re on a modern version and seeing this error:

• Check Mojang’s service status - authentication servers may be temporarily down
• Restart your server and try again after a few minutes
• Ensure your server has internet connectivity

Server Won’t Start (Immediate Crashing)

If your server fails to start or crashes immediately:

• Double-check that the server .jar file is set correctly in Startup Parameters
• In Startup Parameters, change the Java version and restart your server. You may need to try this a couple of times. Automatic works for 99% of cases
• Make sure any file upload was successful, we recommend using SFTP
• Check Console for specific error messages

Version Compatibility

If you’re having issues with mods or plugins:

• Check the mod/plugin’s compatible version on its download page
• Make sure your Minecraft server has the correct game version installed (Forge, Fabric, Spigot, Paper, etc.)
• Note: Mod loaders such as Forge and NeoForge are different and NOT cross-compatible
• Plugins require Spigot, Paper, or similar server types (not vanilla or Forge)

Connection Refused

If you can’t connect to your server and your error message is just “connection refused” with no information:

• Restart your game and server
• If using mods, make sure you’ve installed the same mods to your own game client
• Ensure you’re connecting with the correct IP address
• Check that your server is actually running in Console

Mismatched Mods or Versions

When trying to connect to a modded server, if you have problems such as mismatched mods:

• Ensure your client has the same mods installed as the server
• Download any missing mods or delete conflicting ones from both client and server