Value cannot be null. Parameter name: entitySet

Question

I have a fairly standard setup with simply POCO classes

public class Project
{

    public int ProjectId { get; set; }
    public string Name { get; set; }
          


        

Answer 1

Late to the game...but if it helps...

I had this same problem, everything was working fine, but this issue appeared, I added the following to one of my classes

public HttpPostedFileBase File { get; set; }

which seemed to break it.

I ensured I didn't map this to the database by using the following:

[NotMapped]
public HttpPostedFileBase File { get; set; }

You need to add the following using statement:

using System.ComponentModel.DataAnnotations.Schema;

Hope this helps