title: No OWIN authentication manager is associated with the request
body: <p>After trying to enable owin &amp; AspNet Identity to my Web Api project (in VS 2013 + .Net 4.5.1) I get the following error in each valid or unvalid(request to none exist controller) requests :</p>
  
  <pre><code>&lt;Error&gt;
  &lt;Message&gt;An error has occurred.&lt;/Message&gt;
  &lt;ExceptionMessage&gt;
  No OWIN authentication manager is associated with the request.
  &lt;/ExceptionMessage&gt;
  &lt;ExceptionType&gt;System.InvalidOperationException&lt;/ExceptionType&gt;
  &lt;StackTrace&gt;
  at System.Web.Http.Owin.PassiveAuthenticationMessageHandler.SuppressDefaultAuthenticationChallenges(HttpRequestMessage request) at System.Web.Http.Owin.PassiveAuthenticationMessageHandler.&lt;SendAsync&gt;d__0.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult() at System.Web.Http.HttpServer.&lt;SendAsync&gt;d__0.MoveNext()
  &lt;/StackTrace&gt;
  &lt;/Error&gt;
  </code></pre>
  
  <p>As I checked in debug mode, no exception is handled too! Also I realized that <code>Configuration</code> in <code>Startup</code> class is never called (indeed never caught by the debugger). here is the code for startup :</p>
  
  <pre><code>[assembly: OwinStartup(typeof(bloob.bloob.Startup))]
  
  namespace bloob.bloob
  {
      public partial class Startup
      {
          public void Configuration(IAppBuilder app)
          {
              ConfigureAuth(app);
          }
      }
  }
  </code></pre>