"Port in use"

Another program already runs on the port the server needs, most often a second copy of the same server. Close it, or click "Switch to a free port" and ProximaClient starts the server on another port.

The app shows a "Port in use" window saying "Port 25565 is already used by another process. Switch the server to a random free port?" or the message "Port 25565 is already taken by another process." (with your server's port instead of 25565).

What to do

Pick one:

• Free the port. Close whatever holds the port: a copy of this same server running in another window or left over from the last start, or another program, such as a second Minecraft server on the standard port 25565. Minecraft server processes are called java.exe and show up in the Windows Task Manager. Then click "Start" again.
• Change the port. Click "Switch to a free port". The app picks a free port, says "Switched to port 41234. Starting..." (with the new port number) and starts the server.

If the server has a tunnel, copy the address again after the port change with the icon next to the external address in the server header (tooltip "Copy address"), not the one next to localhost, and check that your friends get in with it.

If that didn't help

Write to support through "Tech support" in the app menu with the exact error text, the port number and when the error appeared.