System.ArgumentNullException: 'Value cannot be null. Parameter name: e

Question

Hi Team

 

I need some help with this exception, value cannot be empty. This is what i have on my application;

// Model
  public class eNtsaCourses
    {
        [Key]
        public Guid? Id { get; set; }
        public string Course { get; set; }
        public string Nickname { get; set; }
        public string Term { get; set; }
        public string EnrolledAs { get; set; }
        public bool Published { get; set; }
    }

// Controller
    //GET://Courses/Courses-All.
        [Route("Home/Courses")]
      public ActionResult Courses(RegCoursesViewModel eNtsaCourses)
        {
            if(ModelState.IsValid)
            {
                cb.eNtsaCourse.Add(eNtsaCourses.Courses);
                cb.SaveChanges(); // This throws an exception here
            }
            return View(eNtsaCourses);
        }
  [HttpPost]
        public JsonResult AddCoursesRegistration(string CourseName, string clientNo)
        {
            return Json(true, JsonRequestBehavior.AllowGet);
        }