No OWIN authentication manager is associated with the request
asp.net-mvc-5, c#, owin, windows-authentication
Solution
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?
Problem
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); } } } ```