StatusCode: 400, ReasonPhrase: 'Bad Request', Version: 1.1, Content: System.Net.Http.StreamContent, Headers:
{
  Connection: close
  Date: Mon, 01 Aug 2016 08:15:00 GMT
  Server: Microsoft-HTTPAPI/2.0
  Content-Length: 334
  Content-Type: text/html; charset=us-ascii
}

private async void ConnectAsync()
        {
            Connection = new HubConnection(ServerURI);
            Connection.Closed += Connection_Closed;
            HubProxy = Connection.CreateHubProxy("MyHub");
            //Handle incoming event from server: use Invoke to write to console from SignalR's thread
            HubProxy.On<string, string>("AddMessage", (name, message) =>
                this.Invoke((Action)(() =>
                    RichTextBoxConsole.AppendText(String.Format("{0}: {1}" + Environment.NewLine, name, message))
                ))
            );
            try
            {
                await Connection.Start();
            }
            catch (Exception x)
            {
                StatusText.Text = "Unable to connect to server(1): Start server before connecting clients.";
                //No connection: Don't enable Send button or show chat UI
                return;
            }