Заменете това:
include_once 'inc/php/config.php';
include_once 'inc/php/functions.php';
с
include_once dirname(__FILE__) . '/inc/php/config.php';
include_once dirname(__FILE__) . '/inc/php/functions.php';
Заменете това:
include_once 'inc/php/config.php';
include_once 'inc/php/functions.php';
с
include_once dirname(__FILE__) . '/inc/php/config.php';
include_once dirname(__FILE__) . '/inc/php/functions.php';