MVC 6 Entity Scaffolding bug

    public class Quiz
    {
        public int Id { get; set; }
        [Required, MaxLength(255)]
        public string Title { get; set; }
        [Required]
        public DateTime DateCreated { get; set; }
        public Difficulty DifficultyLevel { get; set; }
    }
    public enum Difficulty
    {
        Beginner = 1,
        Intermediate,
        Advanced
    }
   public class Question
    {
        public int Id { get; set; }
        [Required]
        public Quiz Quiz { get; set; }

        [Required]
        public int QuizId { get; set; }

        [Required]
        public string QuestionContent { get; set; }
    }

I created a new controller using MVC + Entity Framework, it generated the following code on Create:

[HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> Create([Bind("Id,QuestionContent,QuizId")] Question question)
        {
            if (ModelState.IsValid)
            {
                _context.Add(question);
                await _context.SaveChangesAsync();
                return RedirectToAction("Index");
            }
            ViewData["QuizId"] = new SelectList(_context.Quizzes, "Id", "Quiz", question.QuizId);
            return View(question);
        }

In my view

@model MeMeA.Guru.Entities.Question

<h2>Create</h2>

<form asp-action="Create">
    <div class="form-horizontal">
        <h4>Question</h4>
        <hr />
        <div asp-validation-summary="ModelOnly" class="text-danger"></div>
        <div class="form-group">
            <label asp-for="QuestionContent" class="col-md-2 control-label"></label>
            <div class="col-md-10">
                <input asp-for="QuestionContent" class="form-control" />
                <span asp-validation-for="QuestionContent" class="text-danger" />
            </div>
        </div>
        <div class="form-group">
            <label asp-for="QuizId" class="col-md-2 control-label"></label>
            <div class="col-md-10">
                <select asp-for="QuizId" class ="form-control" asp-items="ViewBag.QuizId"></select>
            </div>
        </div>
        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Create" class="btn btn-default" />
            </div>
        </div>
    </div>
</form>

<div>
    <a asp-action="Index">Back to List</a>
</div>

@section Scripts {
    @{await Html.RenderPartialAsync("_ValidationScriptsPartial");}
}

The view always generates an error

An unhandled exception occurred while processing the request.
NullReferenceException: Object reference not set to an instance of an object.

Microsoft.AspNetCore.Mvc.Rendering.MultiSelectList.Eval(Object container, String expression)`

I just wanted to let you guys know this error occurs in the default code generation when adding a controller and view.

[barrytang]

This is fixed for the upcoming Dev14 release.

[prafullbhosale]

@bwoodard007 This was a known issue with scaffolding in preview1

The problem is the way the Select list is created in the controller.

ViewData["QuizId"] = new SelectList(_context.Quizzes, "Id", "Quiz", question.QuizId);

This needs to change to

ViewData["QuizId"] = new SelectList(_context.Quizzes, "Id", "Title", question.QuizId);

More details: https://github.com/aspnet/Scaffolding/issues/232