Since updating to VS2013, we receive this error when running our (MCV4) web app:
The controller for path \'/9ac086a69364466a841e03e001f946fd/arterySignalR/pi
On VS2013 @Todd's solution didn't work for me, so I made my own.
Hope it saves you some time.
public static void RegisterRoutes(RouteCollection routes)
{
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
#if DEBUG
routes.IgnoreRoute("{*browserlink}", new { browserlink = @".*__browserLink.*" });
#endif
}