on server side error starting collaboration server port already in use??

on server side I'm getting an error when I launch the server with:
./empire --server --shared_password password --port 1337
"error starting collaboration server port already in use"??

I did already set a listener to that port...

also on the client GUI side, I'm getting refused to connect messages:

```
socket.io.min.js:1 GET https://xxx.xx.xxx.xxx/socket.io/?EIO=3&transport=polling&t=1564004359993-38 net::ERR_CONNECTION_REFUSED
i.create @ socket.io.min.js:1
i @ socket.io.min.js:1
o.request @ socket.io.min.js:1
o.doPoll @ socket.io.min.js:1
n.poll @ socket.io.min.js:2
n.doOpen @ socket.io.min.js:2
n.open @ socket.io.min.js:1
r.open @ socket.io.min.js:1
r @ socket.io.min.js:1
r @ socket.io.min.js:1
n.open.n.connect @ socket.io.min.js:1
(anonymous) @ socket.io.min.js:1
```