从Nutshell API检索潜在客户信息时出错

I have this error:

Server Error. 500. The website encountered an error while retrieving
localhost:8888/mars/examples/retrieve.php. It may be down for maintenance or configured incorrectly.

My current Retrieve.php file, redacting the auth key and username:

#!/usr/bin/env php
<?php

// Configuration:
$apiKey   = 'AUTH KEY';
$username = 'AUTH USERNAME';
// End of configuration

require_once('../NutshellApi.php');
$api = new NutshellApi($username, $apiKey);



$params = array(
    'findLeads' => array('Status' =>0),
);

$result = $api->findLeads ($params);
var_dump($result);


echo "
";

I have placed the file system on dropbox.