How to fix System.Data.Edm.EdmEntityType has no key

Question

Does anybody know how to fix this error:

System.Data.Edm.EdmEntityType: : EntityType \'BlogTags\' has no key defined. Define the key for this EntityTy

Answer 1

Same scenario as @Gilesey. In my case I had to mark the key attribute public,

public int Id { get; set; }