[Dylanblitz]

Actually, I found an easier way. Revert what I told you before

in the includes/function_login.php

Find on Line 135

PHP Code:

function verify_authentication($username, $password, $md5password, $md5password_utf, $cookieuser, $send_cookies)
{
    global $vbulletin; 


After add

PHP Code:

$get_username_query = $vbulletin->db->query_read("SELECT username FROM " . TABLE_PREFIX . "user WHERE email = '" . $vbulletin->db->escape_string(htmlspecialchars_uni($username)) . "'");

    if ($vbulletin->db->num_rows($get_username_query) > 0)
    {
    $get_username_data = $vbulletin->db->fetch_array($get_username_query);
    $username = $get_username_data[username];
    } 


I did that on 3.8.4PL1 on my local system. I was able to login to the forums and ACP.