Error 500, when robot open Phalcon micro app

Hello! Sory my English.

I have Phalcon micro application. When I open my site in a browser, Nginx shows code 200 and no errors in log. But, when robot open my site, Nginx show code 500:

HTTP/1.1 500 Internal Server Error
Server: nginx
Date: Tue, 30 May 2017 08:12:58 GMT
Content-Type: text/html; charset=UTF-8
Connection: keep-alive

Access log:

"HEAD / HTTP/1.1" 500 -

Error log:

PHP Fatal error:  Uncaught Phalcon\\Mvc\\Micro\\Exception: Not-Found handler is not callable or is not defined in /home/srv/http/projects/lorhealth.localhost/public/index.php:19\nStack trace:\n#0 /home/srv/http/projects/lorhealth.localhost/public/index.php(19): Phalcon\\Mvc\\Micro->handle()\n#1 {main}\n  thrown in /home/srv/http/projects/lorhealth.localhost/public/index.php on line 9

public/index.php:

<?php
error_reporting(E_ALL);
define('ROOT_PATH', __DIR__ . '/../');
include ROOT_PATH . 'app/config/config.php';
include ROOT_PATH . 'app/config/loader.php';
$app = new Phalcon\Mvc\Micro();
include ROOT_PATH . 'app/config/services.php';
include ROOT_PATH . 'app/config/routes.php';
$app->handle();

What could be the problem?