Missing Method in MainController

You are seeing this error because the action robots.txt is not defined in controller MainController

If you want to customize this error message, create app/views/errors/missing_action.thtml.

Fatal: Confirm you have created the MainController::robots.txt() in file : app/controllers/main_controller.php

<?php
class MainController extends AppController {
   function robots.txt() {
   }
}
?>