ClassiCube Server Not Showing on the Server List? How to Fix It

A ClassiCube server only appears on the classicube.net list while it sends a heartbeat with public = true and classicube.net can reach its port. MCGalaxy ships with public = false, so the most common fix is to set public = true in properties/server.properties and restart. If the log then says Error while finding URL. Is the port open?, the heartbeat arrives but players cannot reach you, which means a closed TCP port, a firewall or CGNAT.

Work through the checks below in order. Each one has a clear sign in the server log, so you are never guessing.

How the ClassiCube server list works

There is no separate registration step. Every 30 seconds MCGalaxy sends a heartbeat to http://www.classicube.net/heartbeat.jsp with the server name, port, player count, the public flag and a secret salt. classicube.net answers with the server's play link, and MCGalaxy logs it:

Server URL found: http://www.classicube.net/server/play/...

It also writes that link to text/externalurl.txt. If you see that line and the link works in your browser, the server is listed. If heartbeats stop because the server crashed, the PC went to sleep or the internet dropped, the server falls off the list after a short while and comes back on the next successful heartbeat.

Check 1: public is set to true

Open properties/server.properties and find:

public = false

That is the MCGalaxy default. Change it to true, save, and restart the server. With false the heartbeat still runs, so the server still gets a play link for people you share it with, but it stays hidden from the public list.

Stop the server before editing. MCGalaxy saves its settings on shutdown, and an edit made while it runs can be overwritten.

Check 2: the log says "Is the port open?"

If the log shows:

Error while finding URL. Is the port open?

then classicube.net tried to connect back to the port in server.properties and failed. Go through these one at a time:

1. Port forward. Forward that TCP port (25565 unless you changed it) on your router to the local IP of the PC running the server. The steps are in how to port forward a game server.
2. Firewall. Windows Defender Firewall blocks new programs by default. Allow MCGalaxyCLI.exe or the port:

netsh advfirewall firewall add rule name="MCGalaxy" dir=in action=allow protocol=TCP localport=25565

3. Port mismatch. The port value, the router rule and the firewall rule must all be the same number. Changing port without updating the router is a common way to break a working server.
4. listen-ip. listen-ip = 0.0.0.0 listens on every network card. If someone set it to a specific address that no longer exists on the machine, nothing can connect.
5. CGNAT. If your router's WAN address starts with 100.64 to 100.127, or differs from what a "what is my IP" site shows, your provider shares one public address between customers and forwarding cannot work. You need a public IP from your provider, a tunnel, or a server hosted elsewhere. See how to host a game server without port forwarding.

Check 3: no heartbeat line at all

If the log never mentions the URL, the server cannot reach classicube.net on the way out. Check that the machine has working internet and DNS, and that nothing changed HeartbeatURL in server.properties away from http://www.classicube.net/heartbeat.jsp. Corporate, school and some VPS networks block outgoing HTTP from unknown programs.

Check 4: it is listed but players cannot find it

The launcher's Servers list is long and sorted by player count, so a new empty server sits near the bottom. Ask players to type part of your server name in the search box. Also check what name you are actually broadcasting: server-name in server.properties. Color codes are stripped from the listed name, so &cRed&fCraft shows as RedCraft.

"Login failed! Close the game and sign in again."

This kick means name verification failed. With verify-names = true (the default and the safe setting), every player must arrive with a pass key that classicube.net hands out when they click your server in the list or open its play link. Players who type your IP into Direct connect with no key get this message.

Fixes, best first:

• Join from the server list or the play link in text/externalurl.txt, signed in to the launcher.
• If a player was in the launcher for hours, have them sign out and back in, then join again.
• Players on your own home network are let in without a key by default (verify-lan-ips = false), so this only hits people joining over the internet.

Do not turn verify-names off to "fix" it on a public server. Without it, anyone can type an admin's name and join with that rank.

"Server has reached max number of guests"

The server is not full, but the Guest rank is. max-guests defaults to 14 while max-players defaults to 16, and raising one without the other is easy. Set both in server.properties and restart:

max-players = 40
max-guests = 36

Promoting regulars to Builder with /setrank name builder also frees guest slots, since ranked players are not counted against max-guests.

"Server full!"

All max-players slots are taken. Raise max-players, or add trusted players to the VIP list with /vip add name, which lets them join past the cap.

Still not listed

Test from outside your network: open the play link from text/externalurl.txt on a phone with Wi-Fi turned off. If it loads, the server is reachable and listed, and the problem is on the player's side. If not, recheck the port and firewall steps with the server running.

The listing on GamezServers

On a GamezServers ClassiCube server the template sets public = true and the correct port for you, so the server heartbeats and shows on classicube.net from its first start, with no router or firewall to touch. The live console shows the Server URL found line, the file manager opens server.properties for max-players and max-guests, and the server stays online without your PC. For a full self hosted setup, see how to host a ClassiCube server.

FAQ

How long does it take for a ClassiCube server to show on the list?

Usually under a minute. MCGalaxy sends a heartbeat every 30 seconds, and the server appears once classicube.net accepts one with public = true.

Why is my ClassiCube server private even though it is online?

public is false in server.properties, which is the MCGalaxy default. The server still works by play link but is hidden from the list.

Can players join a ClassiCube server by IP?

Yes, through Direct connect in the launcher, but with verify-names on they also need a valid pass key, so joining from the list or the play link is easier.

Does the ClassiCube web client need a separate port?

No. With support-web-client = true, browser players connect through the same TCP port as the desktop client.