SimpleMVC Error

An error occured when processing this action.

Misssing Action-class for action robots.txt (Request URI: /robots.txt)

How to fix this error?

Create the file webapp/actions/robots.txt_action.php with the following contents:

class Robots.txtAction extends Action {

  // Action methods

}

Backtrace

#0  require_once() called at [/www/v3/libs/utils/action_errors.php:11]
#1  ActionErrors::missingAction(robots.txt) called at [/www/v3/libs/action.php:175]
#2  Action::_executeAction() called at [/www/v3/webroot/index.php:31]