ASP.NET SignalR C# Client App Exception on Start

Question

I have a ASP.NET application. I run it by hitting debug. It runs on localhost:2842.

I have a SignalR Hub defined in a class with no methods on the server.

I have a WPF Windows C# application. I added the SignalR NuGet package. I use the following code to instantiate the client proxy:

        var hubConnection = new HubConnection("http://localhost:2842");

        IHubProxy myHubProxy = hubConnection.CreateHubProxy("MyHub");
        myHubProxy.On<string>("SendMeData", dataString => {

            Console.WriteLine("String value {0}", dataString);
        });

        hubConnection.Start().Wait();

Here is my hub class defined on the server:

public class MyHub : Hub
{
    public static void SendMeData(string dataString)
    {
        var context = GlobalHost.ConnectionManager.GetHubContext<MyHub>();
        if (context != null)
            context.Clients.All.SendMeData(dataString);
    }
}

I have this code in Startup.cs:

public partial class Startup
{
    public void Configuration(IAppBuilder app)
    {
        ConfigureAuth(app);

        app.MapSignalR(new HubConfiguration
        {
            EnableDetailedErrors = true
        });
    }
}

The problem I am having is that when the C# client calls hubConnection.Start().Wait(); I get a very unhelpful exception. Here is the exception:

StatusCode: 500, ReasonPhrase: 'Internal Server Error', Version: 1.1, Content:
System.Net.Http.StreamContent, Headers:  Transfer-Encoding: chunked
X-SourceFiles: =?UTF-8?B?QzpcTXlEZXZcUmVhbHRpbWVNRFxSZWFsdGltZU1EUHJvdG9cUmVhbHRpbWVNRFByb3RvXHNpZ25hbHJcbmVnb3RpYXRl?=
Cache-Control: private  Date: Thu, 27 Apr 2017 04:23:18 GMT  Server: Microsoft-IIS/10.0
X-AspNet-Version: 4.0.30319  X-Powered-By: ASP.NET  Content-Type: text/html; charset=utf-8

I set break points in the server code and it never hits any of them.

How do I figure this out?

Answer 1

The whole problem ended up being that I had changed the name of my Hub class in the server without changing the name used in CreateHubProxy. it is working now.