title: Ruby on Rails - Active Admin undefined method `except' for #
body: <p>I'm getting a error in Active Admin when I put some code in my application_controller.rb. The error is (when i try access HomeConfig in active admin):</p>
  
  <p><code>undefined method 'except' for #&lt;HomeConfig:0x007f8877cfda58&gt;</code></p>
  
  <p>In this case, the error occurs when I put this code in application_controller.rb:</p>
  
  <pre><code>class ApplicationController &lt; ActionController::Base
  
    protect_from_forgery with: :exception
  
    # Code that cause the problem
    before_filter :contact_info, :home_config
  
    def contact_info
      @contact_infos = ContactInfo.all
    end
  
    def home_config
      @home_configs = HomeConfig.last
    end
  end
  </code></pre>
  
  <p>And the log of error in terminal:</p>
  
  <pre><code>Started GET "/alumni/admin/home_configs" for 127.0.0.1 at 2018-10-02 09:07:38 -0300
  Processing by Admin::HomeConfigsController#index as HTML
    HomeConfig Load (0.4ms)  SELECT  `home_configs`.* FROM `home_configs`   ORDER BY `home_configs`.`id` DESC LIMIT 1
    AdminUser Load (0.3ms)  SELECT  `admin_users`.* FROM `admin_users`  WHERE `admin_users`.`id` = 1  ORDER BY `admin_users`.`id` ASC LIMIT 1
    Rendered /Users/Atua/.rvm/gems/ruby-2.1.3@facensAlumni/bundler/gems/activeadmin-dce083189c46/app/views/active_admin/resource/index.html.arb (598.9ms)
  Completed 500 Internal Server Error in 644ms
  
  NoMethodError - undefined method `except' for #&lt;HomeConfig:0x007f887c002d58&gt;:
  
  Started POST "/__better_errors/32ad65699eb25cf6/variables" for 127.0.0.1 at 2018-10-02 09:07:39 -0300
    ContactInfo Load (0.3ms)  SELECT `contact_infos`.* FROM `contact_infos`
  </code></pre>
  
  <p>If I withdraw this code and restart the server, everything works fine. Anyone know what happening?</p>
  
  <p>Thanks.</p>