Failed to load database driver.

<?php
/*
 * Flashii Sakura Backend
 * (c)Flashwave/Flashii Media 2013-2015 <http://flash.moe>
 */

// Declare Namespace
namespace Flashii;

// Start output buffering
ob_start();
 
// Define Sakura version
define('SAKURA_VERSION', '20150321');

// Define Sakura Path
define('ROOT_DIRECTORY', str_replace('_sakura', '', dirname(__FILE__)));
 
// Error Reporting: 0 for production and -1 for testing 
error_reporting(-1);

// Include Configuration
require_once ROOT_DIRECTORY .'_sakura/config/config.php';

// Include libraries
require_once ROOT_DIRECTORY .'_sakura/vendor/autoload.php';
require_once ROOT_DIRECTORY .'_sakura/components/Main.php';
require_once ROOT_DIRECTORY .'_sakura/components/Hashing.php';
require_once ROOT_DIRECTORY .'_sakura/components/Configuration.php';
require_once ROOT_DIRECTORY .'_sakura/components/Sessions.php';

// Generate path to database driver
$_DBNGNPATH = ROOT_DIRECTORY .'_sakura/components/database/' . $fiiConf['db']['driver'] . '.php';

// Include database driver
if(file_exists($_DBNGNPATH))
    require_once $_DBNGNPATH;
else
    die('<h1>Failed to load database driver.</h1>');


// Set Error handler
set_error_handler(array('Flashii\Main', 'ErrorHandler'));

// Initialise Flashii Class
Main::init($fiiConf);

// Set base page rendering data
$renderData = array(
    'sakura' => [
        'sakura_version'    => SAKURA_VERSION,
        'urls'              => $fiiConf['urls']
    ]
);