I have this problem. I created the "Topic" action with the parameter "topic" but when I go to "About / Topic? topic = aloha" I can not find this action and I get an error: "Page not found No umbraco document matches the url '/ About / Topic? Topic = aloha'. "

Controller:

public class AboutController : Umbraco.Web.Mvc.RenderMvcController
{
    // GET: About
    public ActionResult About(RenderModel model)
    {
        return View("About", model);
    }

    public ActionResult Topic( string topic)
    {
        return View("About");
    }
}

Routing:

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 }
        );
        routes.MapRoute(
        name: "Default1",
        url: "{controller}/{action}/{topic}",
        defaults: new { controller = "About", action = "Topic", topic = UrlParameter.Optional }
        );
    }