Index: branches/5.3.x/core/kernel/startup.php
===================================================================
diff -u -N -r15962 -r16124
--- branches/5.3.x/core/kernel/startup.php	(.../startup.php)	(revision 15962)
+++ branches/5.3.x/core/kernel/startup.php	(.../startup.php)	(revision 16124)
@@ -1,6 +1,6 @@
 <?php
 /**
-* @version	$Id: startup.php 15962 2013-09-03 15:13:13Z alex $
+* @version	$Id: startup.php 16124 2015-01-01 14:06:22Z alex $
 * @package	In-Portal
 * @copyright	Copyright (C) 1997 - 2009 Intechnic. All rights reserved.
 * @license      GNU/GPL
@@ -65,6 +65,12 @@
 
 	define('SERVER_NAME', $http_host);
 
+	if ( !file_exists(FULL_PATH . '/vendor/autoload.php') ) {
+		echo 'Cannot find an "/vendor/autoload.php" file, have you executed "composer install" command?<br/>';
+		flush();
+		exit;
+	}
+
 	// variable WebsitePath is auto-detected once during installation/upgrade
 	define('BASE_PATH', $vars['WebsitePath']);
 
@@ -183,6 +189,7 @@
 			KERNEL_PATH . "/db/dbitem.php",
 			KERNEL_PATH . "/event_handler.php",
 			KERNEL_PATH . '/db/db_event_handler.php',
+			FULL_PATH . '/vendor/autoload.php',
 	);
 
 	foreach ($includes as $a_file) {
@@ -195,4 +202,4 @@
 
 	// system users
 	define('USER_ROOT', -1);
-	define('USER_GUEST', -2);
\ No newline at end of file
+	define('USER_GUEST', -2);