A copy of AttributeProvider has been removed from the module tree but is still active

[ck2000]

Iam getting an ArgumentError in Excption in row "CustomerAttribute.where(company_id: model.company_id)" of the following code. What I am trying to do is load dynamic attributes per each customer. My AttrivuteProvider is located at rails_root/lib/attribute_provider.rb
How can I solve this issue?

class
 AttributeProvider
  def initialize(model)
    @model = model
  end
  CustomerAttribute.where(company_id: model.company_id).map do |field|
      ActiveDynamic::AttributeDefinition.new(field.name,
                                             datatype: 2, #field.datatype,
                                             required: field.required,
                                             default_value: field.default_value)
    end
  end
private
  attr_reader :model
end

ActiveDynamic.configure do |config|
  config.provider_class = AttributeProvider
  config.resolve_persisted = Proc.new { |model| model.is_a?(Employment) ? true  : false }
end