The server port is already in use
What it looks like in your log
**** FAILED TO BIND TO PORT! The exception was: java.net.BindException: Address already in use
What causes it
Another program, often another Minecraft server, is already using this port.
How to fix it
Stop the other server, or change server-port in server.properties.
Why it happens
The server asked the operating system to listen on its port and was told the port already has a listener. Nine times out of ten that listener is the previous copy of the same server, still shutting down or hung after a crash. The rest are a second server configured on the same port, or another program that happens to use 25565.
Fix it step by step
- 1Find what has the portOn Linux, ss -ltnp | grep 25565 names the process. On Windows, netstat -ano | findstr 25565 gives the PID. On a hosted panel, the previous server process is the answer and a force-stop clears it.
- 2Stop itIf it is the old server, wait for it to finish or kill it. If it is another server, change one of them.
- 3Change the port if you meant two serversserver-port in server.properties. Two servers on one machine cannot share a port; give the second one 25566 and forward it separately.
- 4RestartThe bind succeeds and the server continues booting.
If that didn't work
On Docker, "port is already allocated" is the container engine reporting the same clash one layer up: another container publishes the same host port. Change the mapping.
Not sure this is your problem? Paste your log and Roastd will tell you which of these it actually matched, and what else it found.
Check your own log