Why doesn't Devise authorize the omniauth-vkontakte gem?

Question

Ruby on Rails

I do authorization Devise+Omniauth+google+facebook+vk. Everything works except for the omniauth-vkontakte gem, when clicked, authorization does not occur, but throws at domain/users/sign_up, what could be the error?

app/models/user.rb 

devise :omniauthable, :omniauth_providers => [:google_oauth2, :facebook, :vkontakte] 

def self.find_for_vkontakte_oauth(auth, signed_in_resource=nil) 
    user = User.where(:provider => auth.provider, :uid => auth.uid).first 
    if user 
      return user 
    else 
      registered_user = User.where(:email => auth.info.email).first 
      if registered_user 
        return registered_user 
      else 
        user = User.create(name:auth.extra.raw_info.name, 
                           provider:auth.provider, 
                           uid:auth.uid, 
                           email:auth.info.email, 
                           password:Devise.friendly_token[0,20], 
        ) 
      end    end 
  end

app/controllers/users/omniauth_callbacks_controller.rb 

 def vkontakte 
    @user = User.find_for_vkontakte_oauth(request.env["omniauth.auth"], current_user) 
    if @user.persisted? 
      set_flash_message(:notice, :success, :kind => "Vkontakte") if is_navigational_format? 
      sign_in_and_redirect @user, :event => :authentication 
    else 
      session["devise.vkontakte_data"] = request.env["omniauth.auth"].except("extra") 
      redirect_to new_user_registration_url 
    end 
  end 

config/initializers/devise.rb 
config.omniauth :vkontakte, "546546545", "fdgnG1fdgxgVefdgO", 
    { 
      :scope => 'friends,audio,photos', 
      :display => 'popup', 
      :lang => 'en', 
      :image_size => 'original' 
    }

Answer 1

Problem solved, just needed to add to :scope email

config/initializers/devise.rb
config.omniauth :vkontakte, "345435", "fgfgdfgfdgdfgdfgdg",
    {
      :scope => 'friends,audio,photos,email',
      :display => 'popup',
      :lang => 'en',
      :image_size => 'original'
    }