title: HTTP 503 Service is unavailable when trying to browse signalr/hubs
body: <p>I have a windows hosted SignalR hub created in VS2012:</p>
  
  <pre><code>public class Startup
  {
      public void Configuration(IAppBuilder app)
      {
          app.UseCors(CorsOptions.AllowAll);
          app.MapSignalR();
      }
  }
  
  public static class SignalR
  {
      public static void Start()
      {
          const string url = "http://*:8080";
          WebApp.Start&lt;Startup&gt;(url);
      }
  }
  
   public class Broadcaster : Hub
      {
  
          public void SendDownloadResult(bool result, string device, string description, string connectionId, string task)
          {
              var context = GlobalHost.ConnectionManager.GetHubContext&lt;Broadcaster&gt;();
              context.Clients.Client(connectionId).sendDownloadResult(result, device, description, task);
          }
      }
  </code></pre>
  
  <p>I have deployed this windows service on 3 different PCs, it works fine on two PCs, but on the other, I get HTTP 503 Service is unavailable when I try to browse <code>http://localhost:8080/signalr/hubs</code></p>
  
  <p>No exception thrown when the code is executed on all 3 PCs.</p>
  
  <p>I have checked IIS's features in add/remove windows features, they're all the same.</p>
  
  <p>What am I missing? </p>