Fix "Failed to bind to port" on Minecraft

Players cannot join because the server stopped at start-up with **** FAILED TO BIND TO PORT! in the Console. Java could not attach the server to its network port. The panel sets the game's own port for you and you never need to open it, so you do not edit that one, but an add-on with a port setting of its own is worth checking. Java's documentation says a failed bind typically means the port is already in use, so this guide checks what on your server could be holding it.

Checked against Minecraft 26.3's server files, the OpenJDK 25 documentation and the current panel, October 2026.

What the error says

Minecraft prints three lines together: **** FAILED TO BIND TO PORT!, then The exception was: followed by the Java error, then Perhaps a server is already running on that port?. The line after The exception was: names the cause. It may be a Netty NativeIoException with bind(..) failed in its text, or a java.net.BindException. When the port is already taken, the Netty error includes Address already in use. The OpenJDK documentation describes a BindException as a failure to bind a socket to a local address and port, and says that typically the port is in use or the address could not be assigned.

Check your port

The port is fixed for your server, and the panel writes it into server.properties at every start. It does the same for server-ip. The Config Editor does not show those two keys, and a hand edit in the File Manager is overwritten at the next start, so changing them cannot fix this.

To see the port, open Settings under More, then the Network ports card under Connections. The row with the Primary badge is the port players join on. Rows with the Extra badge are ports you added for other tools.

Fix 1: something still holds the port

Only one program can listen on a port at a time. If an earlier run of the server has not finished stopping, anything it still holds on the port stops the new start from taking it.

1. Open the Console tab and click Stop. Wait until the status reads Offline.
2. If Stop hangs, click Force stop and confirm. It skips the graceful shutdown, so anything the game had not saved can be lost. Use it only when Stop does not work.
3. Click Start once and wait for the Done line.

Fix 2: something else is set to the same port

Check anything that opens a port of its own, such as a web map like Dynmap or BlueMap or a voice chat mod. The Network ports card says extra ports are for things like plugin web maps and voice mods, and that each needs its own port. So an add-on should not use the Primary port, which the game uses. Open its config file in the File Manager and make sure its port is one of your Extra ports, not the Primary one. Add an extra port first if you have none. Add an extra port to your server shows how.

Things you do not need

You do not need to open the primary port yourself. Players join on it, and Add an extra port to your server notes that you never need to open it.

If it keeps happening

Click Download Log on the Console tab, choose Last hour, and send it with your server name through Contact support and open a ticket. For other start-up messages, see Fix a Minecraft server that will not start.