Missing Controller

Error: GristMill.htmlController could not be found.

Error: Create the class GristMill.htmlController below in file: app/controllers/grist_mill.html_controller.php

<?php
class GristMill.htmlController extends AppController {

	var $name = 'GristMill.html';
}
?>

Notice: If you want to customize this error message, create app/views/errors/missing_controller.ctp