[eleetoburrito]

I'm using this code from another thread

<?php

chdir("forum/core/"); // change to your core folder location
require_once("global.php");

function create_random_user(){
    $dataman =& datamanager_init('User', $vbulletin);  
    $dataman->set('username', "user".rand());
    $dataman->set('email', rand()."@domain.com");
    $dataman->set('password', "leighf");
    return $dataman->save();
}

function log_user_in($userid){
    $user = fetch_userinfo($userid);
    $auth = vB_User::verifyAuthentication($user['username'], "leighf", $user['password'], $user['password']);
    $res = vB_User::processNewLogin($auth);
    vbsetcookie('userid', $res['userid']); 
    vbsetcookie('password', $res['password']);
    vbsetcookie('sessionhash', $res['sessionhash']);
}

// create random user
$userid = create_random_user();

// log them in
log_user_in($userid);

Everything works fine, but when I try to login a user from the existing database, if the password is bad and the auth doesn't work, this error shows up

Fatal error: Class 'vB_Router' not found in /home/public_html/forum/core/vb/exception/user.php on line 40

Why is that? How do I fix this?