Update routes.rb

add get method for 'admin/archive_files/categories_order'

config/routes.rb

@@ -5,6 +5,7 @@ locales = Site.find_by(site_active: true).in_use_locales rescue I18n.available_l
   scope "(:locale)", locale: Regexp.new(locales.join("|")) do
    namespace :admin do
       resources :archive_files
+      get 'archive_files/categories_order' => 'archive_files#categories_order'
    end
    get "/xhr/archive/download" => "archives#download_file"
   end