Sent non-empty 'Sec-WebSocket-Protocol' header but no response was received

[MrBlaTi]

I'm trying to fire up a server using

this.server = new Server(11112);
this.server.start();

using

public Server(int port) throws UnknownHostException {
        super(new InetSocketAddress(port));
    }

And I try to connect to it using the standart js websocket api
but i keep getting the error

WebSocket connection to 'ws:https://192.168.0.13:11112/' failed: Error during WebSocket handshake: Sent non-empty 'Sec-WebSocket-Protocol' header but no response was received
general.js (4,0)

any ideas?
edit:nvm found the error