Routing attribute in area

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MVC

MVC5

ASP.NET5

Hi guys,
I want to use route attribute in area but i could not.

it's RouteConfig.cs

public class RouteConfig
   {
       public static void RegisterRoutes(RouteCollection routes)
       {
           routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
           routes.MapMvcAttributeRoutes();
           routes.MapRoute(
               name: "Default",
               url: "{controller}/{action}/{id}",
               defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }, namespaces: new[] {"OgrenciEvi.Controllers"}
           );

       }
   }

Area/Manager/UniversityController;

[RouteArea("Manager")]
   public class UniversityController : Controller
   {
       SiteContext db = new SiteContext();

       // GET: Manager/University

       [Route("BuildingAdd/{UniID?}")]
       public ActionResult BuildingAdd(int UniID)
       {
           ViewBag.UniList = new SelectList(db.University, "UniID", "UniName");
           return View();
       }

       [HttpPost]
       public ActionResult BuildingAdd(BuildingModel NewBuilding)
       {
           if (Request.Form["btnSave"] != null)
           {
               if (ModelState.IsValid)
               {
                   db.Building.Add(NewBuilding);
                   db.SaveChanges();
               }
           }

           return RedirectToAction("BuildingAdd", "University", new { uniid = NewBuilding.UniID});
       }
   }

BuildingApp page's url should be "/Manager/University/BuildingAdd/5" or "/Manager/University/BuildingAdd"

but I got "Source could not find" error.

What I have tried:

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