[Kane@airrifle]

Change the red text to mysqli in includes/config.php

<?php
/*======================================================================*\
|| #################################################################### ||
|| # vBulletin 3.8.9 Patch Level 1
|| # ---------------------------------------------------------------- # ||
|| # All PHP code in this file is ?2000-2017 vBulletin Solutions, Inc. # ||
|| # This file may not be redistributed in whole or significant part. # ||
|| # ---------------- VBULLETIN IS NOT FREE SOFTWARE ---------------- # ||
|| # http://www.vbulletin.com | http://www.vbulletin.com/license.html # ||
|| #################################################################### ||
\*======================================================================*/

/*-------------------------------------------------------*\
| ****** NOTE REGARDING THE VARIABLES IN THIS FILE ****** |
+---------------------------------------------------------+
| If you get any errors while attempting to connect to    |
| MySQL, you will need to email your webhost because we   |
| cannot tell you the correct values for the variables    |
| in this file.                                           |
\*-------------------------------------------------------*/

	//	****** DATABASE TYPE ******
	//	This is the type of the database server on which your vBulletin database will be located.
	//	Valid options are mysql and mysqli, for slave support add _slave.  Try to use mysqli if you are using PHP 5 and MySQL 4.1+
	// for slave options just append _slave to your preferred database type.
$config['Database']['dbtype'] = 'mysql';