Entity framework ForeignKeyAttribute on property … on type … is not valid

I get this error:

The ForeignKeyAttribute on property 'SubdivisionsHOA' on type 'HealthOfAustralia.DAL.Models.ContentArticleHOAsubdivision' is not valid. The foreign key name 'SubdivisionHOAId' was not found on the dependent type 'HealthOfAustralia.DAL.Models.SubdivisionHOA'. The Name value should be a comma separated list of foreign key property names.

Here are the model classes:

public partial class ContentArticleHOAsubdivision
{
    public int Id { get; set; }
    public long ContentArticleId { get; set; }
    public short SubdivisionHOAId { get; set; }

    [ForeignKey("ContentArticleId")]
    public virtual ContentArticleHOA ContentArticleHOA { get; set; }
    [ForeignKey("SubdivisionHOAId")]
    public virtual ICollection<SubdivisionHOA> SubdivisionsHOA { get; set; }
}

public partial class SubdivisionHOA
{
    [Key, ForeignKey("TopTierDivisionHOA")]
    public short Id { get; set; }
    public string Name { get; set; }

    public virtual TopTierDivisionHOA TopTierDivisionHOA { get; set; }
}

What am I doing wrong?