ASP.NET MVC 4 Bundles giving 404 error

I want to add Bundles into an existing ASP.NET MVC 4 (.NET 4.5) website that uses:

• Umbraco 6.1.5
• Microsoft ASP.NET Web Optimization Framework 1.1.3 (https://www.nuget.org/packages/microsoft.aspnet.web.optimization/)

I attempted to follow these directions: https://gist.github.com/jkarsrud/5143239, and the CSS loaded fine before I started down the bundles path.

On page load it inserts the style reference:

<link href="/bundles/marketingcss" rel="stylesheet">

But a 404 error happens:

> GET http://localhost:20459/bundles/marketingcss 404 (Not Found) 

Here's what I've in code:

Web.Config

<add key="umbracoReservedPaths" value="~/umbraco,~/install/,~/bundles" />

Global.asax

<%@ Application Codebehind="Global.asax.cs" Inherits="MapCom.Global" Language="C#" %>

Global.asax.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Optimization;
using System.Web.Security;
using System.Web.SessionState;
using Umbraco.Web;

namespace MapCom
{
    public class Global : UmbracoApplication
    {
        protected void Application_Start(object sender, EventArgs e)
        {
            base.OnApplicationStarted(sender, e);
            BundleConfig.RegisterBundles(BundleTable.Bundles);
        }
    }
}

_Layout.cshtml

@Styles.Render("~/bundles/marketingcss");

BundleConfig.cs

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

namespace MapCom
{
    public class BundleConfig
    {
        public static void RegisterBundles(BundleCollection bundles)
        {
            BundleTable.EnableOptimizations = true;
            ///
            ///Marketing Site CSS Bundle
            ///
            bundles.Add(new StyleBundle("~/bundles/marketingcss")
                .Include("~/plugins/bootstrap/css/bootstrap.min.css")
                .Include("~/css/font-awesome.min.css")
                .Include("~/plugins/parallax-slider/css/parallax-slider.css")
                .Include("~/css/combinedStyles.min.css")
                .Include("~/plugins/ladda-buttons/css/ladda.min.css")
                .Include("~/plugins/ladda-buttons/css/custom-lada-btn.css"));
        }
    }
}

Any ideas?

After much digging into Umbraco, I noticed that the project I'm working on is utilizing a class:

 public class ApplicationEventHandler : IApplicationEventHandler

Which is explained in more detail here: http://our.umbraco.org/documentation/Reference/Events/application-startup

But the gist is:

In order to bind to certain events in the Umbraco application you need to make these registrations during application startup. Based on the Umbraco version you are using there are various ways to hook in to the application starting. The higher the version you are using the more robust this becomes.

So Umbraco's overriding some of the ASP.NET start-up methods.

I solved my issue by adding a reference to System.Web.Optimization in ApplicationEventHandler.cs and moved my bundle registration to this method in that class:

public void OnApplicationStarted(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
{
    RouteConfig.RegisterRoutes(RouteTable.Routes);
    BundleConfig.RegisterBundles(BundleTable.Bundles);
}