bind: address already in use
Something is already using the port your server wants — usually the previous copy of the server that never fully closed.
Do this first
Make sure no other copy of the server is running, then start it again.
What it means
Something is already listening on the port FXServer wants, so it cannot start. The default is 30120 on both TCP and UDP.
What causes it
Ordered by how often it is the answer.
- 1
The previous server is still running
Closing the console window does not always kill FXServer. A zombie process holds the port.
- 2
Two servers configured for the same port
A dev instance and a live instance both on 30120.
- 3
txAdmin already started it
Starting the server by hand while txAdmin has it running.
- 4
Another application on the port
Rare on 30120, common if the port was changed to something ordinary.
- 5
The port is in TIME_WAIT after a hard kill
Clears itself in a minute or two.
How to tell which one is yours
# Windows netstat -ano | findstr :30120 # Linux ss -lptn 'sport = :30120'
The PID it names is what is holding the port. If it is another FXServer, that is your answer.
Where to look
endpoint_add_tcp and endpoint_add_udp in server.cfg.
How to fix it
Kill the old process, or move this one:
endpoint_add_tcp "0.0.0.0:30125" endpoint_add_udp "0.0.0.0:30125"
Both lines must change together — a mismatched pair produces a server that starts and that nobody can join.
Still stuck on your own code?
This page is what this error usually means. Paste your console into Server Fixer and it will rank everything in it and tell you what to do first, and if you would rather not touch it, ORBIE can repair the script and hand the resource back ready to drop in.
bug_reportOpen Server Fixer