Error when running cucumber

cucumber_error.log

@javascript
  Scenario: Returning to a form placement                                                                                            # features/collection.feature:12
    When a contact returns to a form placement completed previously                                                                  # features/step_definitions/engine_steps.rb:132
      Unable to load URL: http://api.lvh.me:4433/placements/test (Capybara::Driver::Webkit::WebkitInvalidResponseError)
      ./features/step_definitions/engine_steps.rb:29:in `/^a contact visits a page with an? (\w+) placement$/'
      features/collection.feature:13:in `When a contact returns to a form placement completed previously'