Symptoms: Address already in use: :25565, Failed to bind to port, EADDRINUSE
Possible Causes
- Another server is using the same port
- A crashed old process is still running
- A system service is blocking the port
Step-by-Step Fix
Step 1
Find the process using the port
sudo lsof -i :25565Step 2
Terminate the old process
sudo kill -9 <PID>Step 3
Or use a different port
server-port=25566Step 4
Check every Java process
ps aux | grep java