Unable to resolve types in Unity MVC

My MVC project using Unity has suddenly stopped resolving types in my controllers. I'm comparing the setup with a freshly made mvc application with the Unity nuget package - and I caot see any differences. My applicaton worked previously.

I'm tempted to start a fresh application and slowly moving code over from this application to start identifying the problem, but figured I could ask here to get some useful help.

Global.asax.cs

protected void Application_Start()
{
    log4net.Config.XmlConfigurator.Configure();

    AreaRegistration.RegisterAllAreas();
    GlobalConfiguration.Configure(WebApiConfig.Register);
    FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
    RouteConfig.RegisterRoutes(RouteTable.Routes);
    BundleConfig.RegisterBundles(BundleTable.Bundles);

    UnityConfig2.GetConfiguredContainer().AddNewExtension<Log4NetExtension>();
    UnityConfig2.GetConfiguredContainer().RegisterType<ITest, Test>();           
}

UnityMvcActivator.cs

[assembly: WebActivatorEx.PreApplicationStartMethod(typeof(xxx.App_Start.UnityWebActivator), "Start")]
[assembly: WebActivatorEx.ApplicationShutdownMethod(typeof(xxx.App_Start.UnityWebActivator), "Shutdown")]

namespace xxx.App_Start
{
    /// <summary>Provides the bootstrapping for integrating Unity with ASP.NET MVC.</summary>
    public static class UnityWebActivator
    {
        /// <summary>Integrates Unity when the application starts.</summary>
        public static void Start()
        {
            var container = UnityConfig2.GetConfiguredContainer();

            FilterProviders.Providers.Remove(FilterProviders.Providers.OfType<FilterAttributeFilterProvider>().First());
            FilterProviders.Providers.Add(new UnityFilterAttributeFilterProvider(container));

            var resolver = new UnityDependencyResolver(container);
            DependencyResolver.SetResolver(resolver);

            // TODO: Uncomment if you want to use PerRequestLifetimeManager
            Microsoft.Web.Infrastructure.DynamicModuleHelper.DynamicModuleUtility.RegisterModule(typeof(UnityPerRequestHttpModule));
        }

        /// <summary>Disposes the Unity container when the application is shut down.</summary>
        public static void Shutdown()
        {
            var container = UnityConfig2.GetConfiguredContainer();
            container.Dispose();
        }
    }
}

In my HomeController.cs file I just add a dependency:

[Dependency]
public ITest test { get; set; }

With this setup I get an exception: The current type, xxx.ITest, is an interface and caot be constructed. Are you missing a type mapping?

If I put a breakpoint after the RegisterType<>() method call and execute

UnityConfig2.GetConfiguredContainer().Resolve<ITest>()

within the Immediate Window resolution succeeds.

Anyone have any ideas on how to further investigate this issue?