No OWIN authentication manager is associated with the request

Question

After trying to enable owin & 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 :

<Error> <Message>An error has occurred.</Message> <ExceptionMessage> No OWIN authentication manager is associated with the request. </ExceptionMessage> <ExceptionType>System.InvalidOperationException</ExceptionType> <StackTrace> at System.Web.Http.Owin.PassiveAuthenticationMessageHandler.SuppressDefaultAuthenticationChallenges(HttpRequestMessage request) at System.Web.Http.Owin.PassiveAuthenticationMessageHandler.<SendAsync>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.<SendAsync>d__0.MoveNext() </StackTrace> </Error> 

As I checked in debug mode, no exception is handled too! Also I realized that Configuration in Startup class is never called (indeed never caught by the debugger). here is the code for startup :

[assembly: OwinStartup(typeof(bloob.bloob.Startup))]  namespace bloob.bloob {     public partial class Startup     {         public void Configuration(IAppBuilder app)         {             ConfigureAuth(app);         }     } } 

Answer 1

I found the problem finally! After comparing line by line with a newly created project and finding no difference , I checked references on both projects and yes!... All the problem was from missing package :

Microsoft.Owin.Host.SystemWeb 

I don't know why this packaged is missed in package installation phase but the strange point is that why didn't any build exception thrown? or no any dll reference error?

Answer 2

I originally created the project with authentication, but then decided to disable it. I had to remove this in the WebApiConfig.cs file. Make sure you have this if you intend to enable authentication.

        // Web API configuration and services         // Configure Web API to use only bearer token authentication.         config.SuppressDefaultHostAuthentication();         config.Filters.Add(new HostAuthenticationFilter(OAuthDefaults.AuthenticationType));