EF:房产'；街道'；不是类型'；的已声明属性；地址'；

当我尝试使用Entity Framework 6.1获取所有Suppliers时，会出现以下错误。

属性"Street"不是类型"Address"的已声明属性。验证该属性是否未从通过使用Ignore方法或NotMappedAttribute数据注释创建模型。请确保它是一个有效的基元属性。

我的实体看起来是这样的：

供应商.cs:

public class Supplier : AggregateRoot
{
    // public int Id: defined in AggregateRoot class
    public string CompanyName { get; private set; }
    public ICollection<Address> Addresses { get; private set; }
    protected Supplier() { }
    public Supplier(string companyName)
    {
        CompanyName = companyName;
        Addresses = new List<Address>();
    }
    public void ChangeCompanyName(string newCompanyName)
    {
        CompanyName = newCompanyName;
    }
}

地址.cs:

public class Address : ValueObject<Address>
{
    // public int Id: defined in ValueObject class
    public string Street { get; }
    public string Number { get; }
    public string Zipcode { get; }
    protected Address() { }
    protected override bool EqualsCore(Address other)
    {
        // removed for sake of simplicity
    }
    protected override int GetHashCodeCore()
    {
        // removed for sake of simplicity
    }
}

我还定义了两个映射：

SupplierMap.cs

public class SupplierMap : EntityTypeConfiguration<Supplier>
{
    public SupplierMap()
    {
        // Primary Key
        this.HasKey(t => t.Id);
        // Properties
        this.Property(t => t.CompanyName).IsRequired();
    }
}

AddressMap.cs

public class AddressMap : EntityTypeConfiguration<Address>
{
    public AddressMap()
    {
        // Primary Key
        this.HasKey(t => t.Id);
        // Properties
        this.Property(t => t.Street).IsRequired().HasMaxLength(50);
        this.Property(t => t.Number).IsRequired();
        this.Property(t => t.Zipcode).IsOptional();
    }
}

但当我运行以下代码时，我会给出上面描述的错误：

using (var ctx = new DDDv1Context())
{
    var aaa = ctx.Suppliers.First(); // Error here...
}

当我从Supplier.cs类中删除ICollection，并从我的数据库上下文中删除映射类时，代码就工作了：

public class DDDv1Context : DbContext
{
    static DDDv1Context()
    {
        Database.SetInitializer<DDDv1Context>(null);
    }
    public DbSet<Supplier> Suppliers { get; set; }
    public DbSet<Address> Addresses { get; set; } //Can leave this without problems
    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
        modelBuilder.Configurations.Add(new SupplierMap());
        // Now code works when trying to get supplier
        //modelBuilder.Configurations.Add(new AddressMap());
    }
}

当我尝试将代码与Address类和AddresMap类一起使用时，为什么代码会出现错误？