No OWIN authentication manager is associated with the request
问题 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