ActionController::MissingRenderer Ruby on Rails 5.1.2 Class ActionController::MissingRenderer < LoadError actionpack/lib/action_controller/metal/renderers.rb See Responder#api_behavior Methods N new Class Public methods new(format) Link Source: show | on GitHub # File actionpack/lib/action_controller/metal/renderers.rb, line 16 def initialize(format) super "No renderer defined for format: #{format}" end