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

I have some properties in "ExpenseModel", one of this was...

public virtual Type TypeId {get; set;}

which was causes the above same error because of "Type" propertyType, so I changed
"Type" => "ExpenseType" and it worked... :-)

public virtual ExpenseType TypeId {get; set;}

ExpenseModel.cs

public class ExpenseTypes
{
    [Key]
    public int Id { get; set; }
    public string TypeName { get; set; }
    public string Description { get; set; }
}