I can't make a hubConnection in signalR

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C#

I have a server code as shown below and client code further below. In the Client code I am trying to start a HubConnection but I keep getting an System.AggregateException when I include .Wait() on

connection.Start()

namespace SignalRServer
{
    public class Program
    {
        static void Main(string[] args)
        {
            string url = "http://localhost:8080";

            using (WebApp.Start<StartUp>(url))
            {
                Console.WriteLine("Server running on {0}", url);
                Console.ReadLine();
            } 
        }
    }
    class StartUp
    {
        public void Configuration(IAppBuilder app)
        {
            app.MapSignalR();
        }
    }

}

My Client Code

var connection = new HubConnection("http://localhost:8080");
            var my_hub = connection.CreateHubProxy("ChatHub");

            connection.Start().Wait();