SignalR: Sending data using GlobalHost.ConnectionManager not working

When using a custom dependency resolver, it is not enough to pass it to the HubConfiguration.

You need to either store the resolver instance somewhere and use it like this to access the connection manager and your hub context:

MyDependencyResolver.Resolve<IConnectionManager>().GetHubContext<MyHub>();

or set the default dependency resolver in GlobalHost to your instance:

var myResolver = new SignalRUnityDependencyResolver(unityContainer);
RouteTable.Routes.MapHubs( new HubConfiguration() { Resolver = myResolver } );
GlobalHost.DependencyResolver = myResolver;

(then you can use the default GlobalHost.ConnectionManager.GetHubContext<MessageHubBub>())