Probably there's no matching controller or action for that page(View). First of all, why do you need to use Setstartuppage option here? Use
defaults
route.
Check the sample code from this article
Routing Basics in ASP.NET MVC[
^]
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
routes.MapRoute(
name: "Default",
url: "{controller}/{action}/{id}",
defaults: new
{
controller = "Home",
action = "Index",
id = UrlParameter.Optional
}
);
}
}