Index: branches/5.3.x/core/kernel/utility/factory.php
===================================================================
diff -u -N -r16220 -r16326
--- branches/5.3.x/core/kernel/utility/factory.php	(.../factory.php)	(revision 16220)
+++ branches/5.3.x/core/kernel/utility/factory.php	(.../factory.php)	(revision 16326)
@@ -1,6 +1,6 @@
 <?php
 /**
-* @version	$Id: factory.php 16220 2015-09-01 07:33:48Z alex $
+* @version	$Id: factory.php 16326 2016-01-23 19:35:20Z alex $
 * @package	In-Portal
 * @copyright	Copyright (C) 1997 - 2009 Intechnic. All rights reserved.
 * @license      GNU/GPL
@@ -121,6 +121,9 @@
 			$this->namespaceMap[$module_info['ClassNamespace']] = rtrim($module_info['Path'], '/');
 		}
 
+		// Don't let class map builder rely on auto-loader (especially during upgrade).
+		require_once KERNEL_PATH . '/utility/ClassDiscovery/ClassMapBuilder.php';
+
 		if ( defined('IS_INSTALL') && IS_INSTALL ) {
 			// During installation process all modules, because unit configs from all modules are scanned too.
 			$class_map_builders = ClassMapBuilder::createBuilders();