C# MVC返回Json大数据量报错

public ActionResult Act_StudentExtendItemID3(Student_Screen_En En)
        {
            List Stu_ExtendItemID3_List = new List();
            Stu_ExtendItemID3_List = En.GetExtend3Screen();
            //return Json(Stu_ExtendItemID3_List, JsonRequestBehavior.AllowGet);
            System.Web.script.Serialization.JavascriptSerializer serializer = new System.Web.script.Serialization.JavascriptSerializer() { MaxJsonLength = Int32.MaxValue, RecursionLimit = 100 };
            var result = new ContentResult
            {
                Content = serializer.Serialize(Stu_ExtendItemID3_List),
                ContentType = "application/json"
            };
            return result;
        }