为什么我会收到一个Missing type map configuration错误？

我修改了这个ContosoUniversity教程：http://www.asp.net/mvc/tutorials/getting-started-with-ef-using-mvc/creating-an-entity-framework-data-model-for-an-asp-net-mvc-application，现在我正在尝试使用AutoMapper来进行对象之间的映射。

这是我的ModelView：

public class InstructorIndexData
{
    public IEnumerable Instructors { get; set; }
    public IEnumerable Courses { get; set; }
    public IEnumerable Enrollments { get; set; }
    public IEnumerable Students { get; set; }
    public IEnumerable Assignments { get; set; }
}

这是视图：

@model SchoolIn.ViewModels.InstructorIndexData

这是我在控制器中遇到问题的方法。我正在尝试使用这个例子：http://chriscurrie.co.uk/blog/2011/09/coding/net/mvc/use-automapper-to-map-viewmodels-to-entities-mvc3-and-razor/

public class AttendanceController : Controller
{
    private SchoolInDB db = new SchoolInDB();
}

代码在这里...

[HttpPost]
public ActionResult ClassAttendance(InstructorIndexData viewModel)
{
    if (ModelState.IsValid)
    {
        AutoMapper.Mapper.CreateMap();
        AutoMapper.Mapper.CreateMap();
        AutoMapper.Mapper.CreateMap();
        AutoMapper.Mapper.CreateMap();
        Instructor newInstructor = new Instructor();
        Student newStudent = new Student();
        Assignment newAssignment = new Assignment();
        Enrollment newEnrollment = new Enrollment();
        AutoMapper.Mapper.Map(viewModel, newInstructor );
        AutoMapper.Mapper.Map(viewModel, newStudent);
        AutoMapper.Mapper.Map(viewModel, newEnrollment);
        AutoMapper.Mapper.Map(viewModel, newAssignment);
        db.Assignments.AddObject(newAssignment).;
        db.SaveChanges();
        return RedirectToAction("Index");
    }
    return View();
}

当我调试时，我的代码在‘AutoMapper.Mapper.Map(viewModel, newInstructor );’处停止，并显示以下错误：

缺少类型映射配置或不支持的映射。

映射类型：

InstructorIndexData -> Instructor

SchoolIn.ViewModels.InstructorIndexData -> SchoolIn.Models.Instructor

目标路径：

Instructor

源值：

SchoolIn.ViewModels.InstructorIndexData

我还注意到在我的ActionResult(InstructorIndexData viewModel)中，viewModel的所有值都为空。