ruby on rails - Activeadmin, polymorphic relationship and nested attributes -

i have 2 models. there provider , delivery. model note - polymorphic (belongs_to). model provider looks this:

class provider < activerecord::base   attr_accessible :name, :site_url, :brand_ids, :note_attributes   validates :name, presence: true    has_one :note   accepts_nested_attributes_for :note, allow_destroy: true end 

form of creating new provider renders good. when try save

unknown attribute: provider_id 

error. problem?

the note model should have attr_accessible :provider_id