Common Minecraft Server Errors & How to Fix Them

Running a Minecraft server is fun—but sometimes things break. Here's a quick guide to common issues you might run into on your Minecraft server hosted with Final Hosting, and how to fix them.

1. Plugin Conflicts or Server Crashing on Startup

Symptoms:

• Server won’t start

• Console shows errors like:

   

  java.lang.NoClassDefFoundError org.bukkit.plugin.InvalidPluginException

Common Causes:

• Two or more plugins are not compatible

• Plugin version doesn't match your Minecraft version

• Missing dependency plugin (like Vault or PlaceholderAPI)

Fixes:

• Check your plugin versions — make sure they match your server’s version (e.g., Spigot 1.20.1).

• Remove all plugins, then add them back one at a time to find the conflicting one.

• Review console logs for the exact plugin causing the issue.

• Check plugin pages for required dependencies and install them.

???? 2. Out of Memory (OOM) / Server Lagging

Symptoms:

• Console errors like:

   

  java.lang.OutOfMemoryError: Java heap space

• Server lags heavily or crashes under load

Common Causes:

• Too many plugins or large worlds

• Memory-intensive mods

• Not enough RAM allocated to the server

Fixes:

• Upgrade your plan at Final Hosting to get more RAM.

• Remove unnecessary plugins or mods.

• Pre-generate your world using a plugin like Chunky to reduce load.

• Lower your view-distance in server.properties to reduce RAM usage.

⚠️ 3. “Failed to Bind to Port” Error

Symptoms:

• Console shows:

   

  FAILED TO BIND TO PORT Perhaps a server is already running on that port?

Common Causes:

• Server is already running

• Another service is using port 25565

• You set a custom port that’s blocked or already taken

Fixes:

• Check if your server is already running

• make sure you’re only using ports assigned to your server

• If you’ve changed your server port in server.properties, reset it to your servers port unless you know what you’re doing

???? 4. “Unknown Host” When Connecting

Symptoms:

• You or other players get:

   

  Unknown host Can't connect to server

Common Causes:

• Wrong IP address or port used

• DNS not set up if using a custom domain

• Server is offline

Fixes:

• Double-check the IP and port in your Minecraft client

• If using a custom domain (like play.yourserver.com), make sure your DNS is set up correctly

• Check your panel to confirm the server is running

⛔ 5. “You Are Not Whitelisted” or "Can't Join Server"

Symptoms:

• Players can’t join

• Console shows whitelist or ban errors

Common Causes:

• Whitelist is enabled but the player isn’t added

• Player is banned

• online-mode is enabled but user has a cracked client

Fixes:

• Add players using the console:

   

  whitelist add PlayerName

• Disable whitelist in server.properties (white-list=false)

• Check the banned-players.json file in your server files

• If using a cracked client (not recommended), set online-mode=false (but note the risks)

✅ Still Need Help?

If you’ve tried these steps and your server is still having issues, we are here for you!