ArgumentError in ActiveAdmin :: Devise :: Sessions # new Rails 4

Question

Uso le guide 4 + activeadmin su Ruby 1.9.3p392.

Quando vado al

http://127.0.0.1:3000/admin/login 

uri ottengo un errore:

ArgumentError in ActiveAdmin::Devise::Sessions#new

Showing C:/Ruby/lib/ruby/gems/1.9.1/bundler/gems/active_admin-85b9f8164809/app/views/active_admin/devise/sessions/new.html.erb where line #5 raised:

wrong number of arguments (3 for 2)

origine estratti (attorno alla riga # 5):

<h2><%= title "#{render_or_call_method_or_proc_on(self, active_admin_application.site_title)} #{t('active_admin.devise.login.title')}" %></h2> 

<% scope = Devise::Mapping.find_scope!(resource_name) %> 
<%= active_admin_form_for(resource, :as => resource_name, :url => send(:"#{scope}_session_path"), :html => { :id => "session_new" }) do |f| 
    f.inputs do 
    resource.class.authentication_keys.each { |key| f.input key, :input_html => {:autofocus => true}} 
    f.input :password 

Answer 1

ho avuto la lo stesso problema qui e ho risolto la rimozione di gem "meta_search" dal mio Gemfile.