Twitter authorisation error: "success":false,"code":401

hxxp://mydomain.com/assets/components/articles/twitter.auth.php?container=24

{"success":false,"code":401}

require_once dirname(dirname(dirname(dirname(__FILE__)))).'/config.core.php';
require_once MODX_CORE_PATH.'config/'.MODX_CONFIG_KEY.'.inc.php';
require_once MODX_CONNECTORS_PATH.'index.php';

@include(dirname(__FILE__) . '/config.core.php');
if (!defined('MODX_CORE_PATH')) define('MODX_CORE_PATH', dirname(dirname(__FILE__)) . '/core/');
if (!include_once(MODX_CORE_PATH . 'model/modx/modx.class.php')) die();

$modx= new modX('', array(xPDO::OPT_CONN_INIT => array(xPDO::OPT_CONN_MUTABLE => true)));

/* initialize the proper context */
$ctx = isset($_REQUEST['ctx']) && !empty($_REQUEST['ctx']) ? $_REQUEST['ctx'] : 'mgr';
$modx->initialize($ctx);

if (defined('MODX_REQP') && MODX_REQP === false) {
} else if (!$modx->context->checkPolicy('load')) {
    header("Content-Type: application/json; charset=UTF-8");
    header('HTTP/1.1 401 Not Authorized');
    echo $modx->toJSON(array(
        'success' => false,
        'code' => 401,
    ));
    @session_write_close();
    die();
}