undefined method `body=' for "":String for Controller

Building a new controller for my web-app, I stucked on the following problem:

undefined method `body=' for "":String

Rails.root: /User/user/repo/project

Application Trace | Framework Trace | Full Trace

app/controllers/ctrl_controller.rb:9:in `callback

I had the following code:

class CtrlController < ActionController::Base

  def callback

    render :nothing => true

  end

end

Problem was just that the method name callbacl in a ActionController:Base is reserved!

Changing by 'create' solved the problem

class CtrlController < ActionController::Base

  def callback

    render :nothing => true

  end

end