Minecraft Classic servers do not support scanning, and Minecraft Beta only has legacy support. Please remove any query plugins to prevent conflicts.

Enabling Query for Minecraft 1.0+ Servers

To enable scanning, edit your server.properties with:

enable-query=true
query.port=YourQueryPort
motd=YourServerName

To modify your server name and claim your server, you need to change the motd variable.

View http://minecraft.gamepedia.com/Server.properties for more information. For GameServers.com servers, the query port will likely be 25565 or 25566. Users typically have the best results with 25565. Please contact your host for questions regarding the join port and query port.

This has been tested using stock and Bukkit binaries. If it is not working for you, you likely have not opened the server firewall properly or are running an additional plugin that is conflicting (like MinecraftViewer or MCPC+ plugin).

The following may help you further troubleshoot:

1. Have you made the appropriate adjustments to your firewall? If you're hosting from home, have you portforwarded in your router? The port will need to be open for GT to be able to scan your server.
2. Have you confirmed your server is not running any query plugins, like minequery?
3. Are you using the correct query port?
4. Have you added the settings above?
5. Have you tried without mods that are known to break the server query, namely MCPC+ and bungeecord?
6. Have you confirmed you are not blocking the GT scanner IPs?