title: EF Core 2.0 Unable to Determine Relationship
body: <p>I just recently upgraded my solution/project(s) from .NET Core 1.1 to 2.0, including EntityFramework Core.  I am now getting an error I never got from EF Core 1.1.</p>
  
  <p>"Unable to determine the relationship represented by navigation property 'InsurancePolicy.Person' of type 'Person'."</p>
  
  <p>Class/Entity definition is below.</p>
  
  <pre><code>public class InsurancePolicy
  {
      [Key]
      public Guid Id { get; set; }
  
      [ForeignKey( "InsuranceCompanyId" )]
      public InsuranceCompany InsuranceCompany { get; set; }
      [Required]
      public int InsuranceCompanyId { get; set; }
  
      [ForeignKey( "PersonId" )]
      public Person Person { get; set; }
      [Required]
      public Guid PersonId { get; set; }
  
      [ForeignKey( "PolicyHolderId" )]
      public Person PolicyHolder { get; set; }
      [Required]
      public Guid PolicyHolderId { get; set; }
  
      public string GroupId { get; set; }
      public string MemberId { get; set; }
  }
  </code></pre>
  
  <p>If I remove the Person/PersonId property, I just get the same error but on a different entity/property.  Something else is going on or the way this is done in EF 2.0 changed.  This worked fine with EF 1.1 and I was able to run my migration and deploy the database.  After the upgrade to 2.0, I cannot make any calls to my DbContext without getting the above error.</p>