{"action":"opened","issue":{"url":"https://api.github.com/repos/aspnet/EntityFramework/issues/3727","labels_url":"https://api.github.com/repos/aspnet/EntityFramework/issues/3727/labels{/name}","comments_url":"https://api.github.com/repos/aspnet/EntityFramework/issues/3727/comments","events_url":"https://api.github.com/repos/aspnet/EntityFramework/issues/3727/events","html_url":"https://github.com/aspnet/EntityFramework/issues/3727","id":116411845,"number":3727,"title":"\"The derived type '[object]' cannot have keys other than those declared on the root type.\" is throw even if the root type not is mapped.","user":{"login":"Tasteful","id":357589,"avatar_url":"https://avatars.githubusercontent.com/u/357589?v=3","gravatar_id":"","url":"https://api.github.com/users/Tasteful","html_url":"https://github.com/Tasteful","followers_url":"https://api.github.com/users/Tasteful/followers","following_url":"https://api.github.com/users/Tasteful/following{/other_user}","gists_url":"https://api.github.com/users/Tasteful/gists{/gist_id}","starred_url":"https://api.github.com/users/Tasteful/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Tasteful/subscriptions","organizations_url":"https://api.github.com/users/Tasteful/orgs","repos_url":"https://api.github.com/users/Tasteful/repos","events_url":"https://api.github.com/users/Tasteful/events{/privacy}","received_events_url":"https://api.github.com/users/Tasteful/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-11-11T20:08:56Z","updated_at":"2015-11-11T20:08:56Z","closed_at":null,"body":"I tried today to update my solution to RC1 from beta8 and get the exception ```The derived type 'FieldDefinitionEntity' cannot have keys other than those declared on the root type.```. The root type is not mapped, only the derivied type. Should the mapping throw this exception anyway?\r\n```\r\npublic class FieldDefinitionEntity : FieldDefinitionEntityBase\r\n{\r\n    public virtual bool MultiCulture { get; set; }\r\n}\r\n\r\npublic abstract class FieldDefinitionEntityBase\r\n{\r\n    public virtual string FieldType { get; set; }\r\n    public virtual string Id { get; set; }\r\n}\r\n```\r\nMapping\r\n```\r\nbuilder.Entity<FieldDefinitionEntity>(b =>\r\n{\r\n    b.ToTable(\"FieldDefinition\", \"Products\");\r\n    b.HasKey(p => p.Id);\r\n});\r\n```"}}