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 encountered this same issue and resolved like so:

Error in model class:

public class UserInformation
{
    public string ID { get; set; }
    public string AccountUserName { get; set; }
    public HttpPostedFileBase ProfilePic { get; set; }
}

No error in model class

public class UserInformation
{
    public string ID { get; set; }
    public string AccountUserName { get; set; }
    public string ProfilePicName { get; set; }
}

My issue was resolved once i updated the ProfilePic property type from HttpPostedFileBase to string. If you have a property that is not of type string, int, double or some other basic/standard type either replace such property or update to a type which SQL is more likely to accept.