There is no viewdata item of ienumerable<selectitem> error?

System.InvalidOperationException: 'There is no ViewData item of type 'IEnumerable<SelectListItem>' that has the key 'Dashboard.CourseLicence'.'

public ActionResult CourseList()
     {
         List<eNtsaDashboardViewModel> list = new List<eNtsaDashboardViewModel>()
   {
     new eNtsaDashboardViewModel { Text = "Private(Copyrighted)", Value = "1" },
     new eNtsaDashboardViewModel { Text = "Public Domain", Value = "2" },
     new eNtsaDashboardViewModel { Text = "CC Attribution Non Directive", Value = "3" },
     new eNtsaDashboardViewModel { Text = "Creative Commons Licences", Value = "4" },

   };
         ViewBag.list = list;
         return View();
     }

@using (Html.BeginForm("CourseList", "Home", FormMethod.Post))
                                     {
                                     <div class="form-group row">
                                         <label for="Content-Licence" class="col-sm-3 col-form-label">Content Licence</label>
                                         <div class="col-sm-5">
                                             @Html.DropDownListFor(model => model.Dashboard.CourseLicence, ViewBag.list as List<SelectListItem>)
                                         </div>
                                     </div>
                                     }

// eNtsaRegCourses.
  public class RegCoursesViewModel
  {
      public eNtsaCourses Courses { get; set; }
      public eNtsaDashboardViewModel Dashboard { get; set; }
      public List<eNtsaDashboardViewModel> lsteNtsaDashboard { get; set; }
      public RegCoursesViewModel MainModel { get; set; }

  }

// This is for course-list.
 public class eNtsaDashboardViewModel
 {
     public string CourseName { get; set; }

     public string CourseLicence { get; set; }



 }