<NME> controller.rb
<BEF> # encoding: utf-8

require "rango"
require "rango/controller"
require "rango/environments"
require "rango/mixins/rendering"
require "rango/mixins/filters"
require "rango/rack/middlewares/basic"
require "rango/rack/middlewares/basic"

module Rango
  class StackController
    include ExplicitRendering
    include FiltersMixin
    include MessageMixin
end

<MSG> Stack controller has to inherit from Rango::Controller, load helpers

<DFF> @@ -1,6 +1,7 @@
 # encoding: utf-8
 
 require "rango"
+require "rango/helpers"
 require "rango/controller"
 require "rango/environments"
 require "rango/mixins/rendering"
@@ -9,7 +10,7 @@ require "rango/mixins/filters"
 require "rango/rack/middlewares/basic"
 
 module Rango
-  class StackController
+  class StackController < Controller
     include ExplicitRendering
     include FiltersMixin
     include MessageMixin

Stack controller has to inherit from Rango::Controller, load helpers