Web API Attribute Routes in MVC 5 exception: The object has not yet been initialized. Ensure that HttpConfiguration.EnsureInitialized()

Question

On an MVC 5 with Web API I have the following, using only Attribute Routes:

RouteTable.Routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
RouteTable.Routes.IgnoreRoute("{*favicon}", new { favicon = @"(.*/)?favicon.([iI][cC][oO]|[gG][iI][fF])(/.*)?" }); // TODO: Check for Apple Icons

RouteTable.Routes.MapMvcAttributeRoutes();
GlobalConfiguration.Configuration.MapHttpAttributeRoutes();
AreaRegistration.RegisterAllAreas();

In the RouteTable all the MVC routes were created ... But not the API ones ...

I checked the RouteTable.Routes and I see an exception:

The object has not yet been initialized. Ensure that HttpConfiguration.EnsureInitialized() is called in the application's startup code after all other initialization code.

at System.Web.Http.Routing.RouteCollectionRoute.get_SubRoutes() at System.Web.Http.Routing.RouteCollectionRoute.GetEnumerator() at System.Linq.SystemCore_EnumerableDebugView`1.get_Items()

For testing this I added only two Web Api actions to the project:

[RoutePrefix("api")]
public class StatApiController : ApiController {

  [Route("stats/notescreateddaily"), HttpGet]
  public IHttpActionResult NotesCreatedDaily() {
    // Some code
  }

  [Route("stats/userscreateddaily"), HttpGet]
  public IHttpActionResult UsersCreatedDaily() {
    // Some code
  }

}

Am I missing something?

Thank You, Miguel

Answer 1

The solution is in fact replacing:

GlobalConfiguration.Configuration.MapHttpAttributeRoutes();

By:

GlobalConfiguration.Configure(x => x.MapHttpAttributeRoutes());

That was a change in Web API 2.

Answer 2

The solution is to call GlobalConfiguration.Configuration.EnsureInitialized(); after all your Web API related configuration is done, but I am curious as to why your registrations look like this...What kind of project template did you use to create the MVC5 project?...The predefined templates that come with Visual Studio has a structure which helps minimize route ordering problems and so would recommend using them, so wondering why your configuration structure looks like that...

Answer 3

I am having the same problem after I upgrade all my web services project using ASP.Net Web API 4.0 to 4.5 and using Web API 2.2 with Cors library. I managed to successfully solve the problem. What I did was eliminating or commenting out the following statement at the RouteConfig.cs file at App_Start folder:`

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Http;

namespace myNameSpace.Configurations
{
    public static class RouteConfig
    {

        public static void Register(HttpConfiguration config)
        {
            // Web API routes
            //DON'T USE THIS. IT WILL GIVE PROBLEMS IN INSTANTIATION OF OBJECTS
            //config.MapHttpAttributeRoutes();

            config.Routes.MapHttpRoute(
                name: "LocationData",
                routeTemplate: "dataservices/locations/{controller}/{action}/{id}",
                defaults: new {action = "Index", id = RouteParameter.Optional }
            );


            config.Routes.MapHttpRoute(
                name: "ProfileData",
                routeTemplate: "dataservices/profiles/{controller}/{action}/{id}",
                defaults: new { action = "Index", id = RouteParameter.Optional }
            );



            config.Routes.MapHttpRoute(
                name: "DefaultRoute",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );
        }

    }
}

On my Global.asax.cs file I am using the old routing registration

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Http;
using System.Web.Mvc;
using System.Web.Optimization;
using System.Web.Routing;
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
using System.Net.Http.Formatting;

using myNameSpace.IoC;
using myNameSpace.Configurations; // Here actually I change the protected void Application_Start() to protected void Configuration() and change the folder to configuration instead on App_Start
using myNameSpace.Controllers.ExceptionSchema;
using myNameSpace.Filters.HttpFilters;

namespace myNameSpace
{
    public class WebApiApplication : System.Web.HttpApplication
    {
        public static void RegisterApis(HttpConfiguration config)
        {
            config.Filters.Add(new CustomHttpExceptionFilter());
        }
        protected void Application_Start()
        {
            //AreaRegistration.RegisterAllAreas();
            RegisterApis(GlobalConfiguration.Configuration);


            var json = GlobalConfiguration.Configuration.Formatters.JsonFormatter;
            json.SerializerSettings.PreserveReferencesHandling = Newtonsoft.Json.PreserveReferencesHandling.Objects;
            GlobalConfiguration.Configuration.Formatters.Remove(GlobalConfiguration.Configuration.Formatters.XmlFormatter);


            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.Register(GlobalConfiguration.Configuration);
        }
    }
}

Here is the reason: Attribute Routing in Web API 2

Note: Migrating From Web API 1

Prior to Web API 2, the Web API project templates generated code like this:

protected void Application_Start()
{
    // WARNING - Not compatible with attribute routing.
    WebApiConfig.Register(GlobalConfiguration.Configuration);
}

If attribute routing is enabled, this code will throw an exception. If you upgrade an existing Web API project to use attribute routing, make sure to update this configuration code to the following:

protected void Application_Start()
{
    // Pass a delegate to the Configure method.
    GlobalConfiguration.Configure(WebApiConfig.Register);
}

I am using the old route and I decided not to use attribute routing. So take OUT THAT statement