mvc my custom filter throw me exception

public class CookieActionFilter : System.Web.Mvc.ActionFilterAttribute ,IActionFilter
   {

       public override void OnActionExecuting(ActionExecutingContext context)
       {


           if (!cookiesAreEnabled())
           {
               context.Result = new RedirectResult("/Error");
           }

           base.OnActionExecuting(context);
       }

   }

public class HomeController : AppController

protected override void ExecuteCore()
        {
            int culture = 0;
            if (this.Session == null || this.Session["CurrentCulture"] == null)
            {
                int.TryParse(System.Configuration.ConfigurationManager.AppSettings["Culture"], out culture);
                this.Session["CurrentCulture"] = culture;
            }
            else
            {
                culture = (int)this.Session["CurrentCulture"];
            }
            // calling CultureHelper class properties for setting  
            TORWebApplication.Helper.CultureHelper.CurrentCulture = culture;

            base.ExecuteCore();
        }