Q:

DbSet.Load() function missing in EF 6.0

I am trying to access the DbSet<EntityClass>.Load() function to load the entities. This function no longer exists in EF 6.0; upon certain investigation I found that it is a part of the extension methods defined in the EF extension library. 
I get the reference NuGet Packages for EF 6.0 extended library but seems like it's no longer supported. I tried to do an alternative of that function by calling .ToList(), but this method upon processing returns me an inner exception:
({"The column name is not valid. [ Node name (if any) = Extent1,Column name = HasErrors ]"} )
I double checked the mapping class against the database table, but it looks fine. Not sure what I am missing. Below is the code of my mapping class:
internal class CustomerMapping : EntityTypeConfiguration<Customer>
{
    public CustomerMapping()
    {
        this.HasKey(t => t.Id);

        this.Property(t => t.Id).HasColumnName("CUSTOMER_ID");
        this.Property(t => t.Name).HasMaxLength(30).HasColumnName("NAME");
        this.Property(t => t.Email).HasMaxLength(30).HasColumnName("EMAIL");
        this.Property(t => t.PhoneNo).HasMaxLength(100).HasColumnName("PHONE_NO");
        this.Property(t => t.MobileNo).HasMaxLength(100).HasColumnName("MOBILE_NO");
        this.Property(t => t.Address1).HasMaxLength(100).HasColumnName("ADDRESS1");
        this.Property(t => t.Address2).HasMaxLength(100).HasColumnName("ADDRESS2");
        this.Property(t => t.CustomerType).HasMaxLength(100).HasColumnName("CUSTOMER_TYPE");
        this.Property(t => t.Notes).HasMaxLength(100).HasColumnName("NOTES");

        this.ToTable("CUSTOMERS");
    }
}

Below is the actual call made to the database:
internal class EntityService : IEntityService
{
    private ObservableCollection<Customer> customers;

    public DBContextManager DataBaseContext { get; set; }

    public ObservableCollection<Customer> Customers
    {
        get
        {
            if (customers == null && DataBaseContext != null)
            {
               // DataBaseContext.Set<Customer>().Load()
                DataBaseContext.Set<Customer>().ToList();
                customers = DataBaseContext.Set<Customer>().Local;

            }
            return customers;
        }
    }
}

Also please can any one point out the difference between ToList() and Load()?

A:

I found I needed to add:
using System.Data.Entity;

A:

Also, besides System.Data.Entity, you must add the System.Linq namespace as well as System.Windows.

