Index: branches/5.2.x/core/units/themes/themes_eh.php
===================================================================
diff -u -N -r16081 -r16084
--- branches/5.2.x/core/units/themes/themes_eh.php	(.../themes_eh.php)	(revision 16081)
+++ branches/5.2.x/core/units/themes/themes_eh.php	(.../themes_eh.php)	(revision 16084)
@@ -1,6 +1,6 @@
 <?php
 /**
-* @version	$Id: themes_eh.php 16081 2014-10-21 15:46:58Z alex $
+* @version	$Id: themes_eh.php 16084 2014-10-22 08:59:24Z alex $
 * @package	In-Portal
 * @copyright	Copyright (C) 1997 - 2009 Intechnic. All rights reserved.
 * @license      GNU/GPL
@@ -132,6 +132,25 @@
 		}
 
 		/**
+		 * Validate entered stylesheet path.
+		 *
+		 * @param kEvent $event Event.
+		 *
+		 * @return void
+		 */
+		protected function OnBeforeItemUpdate(kEvent $event)
+		{
+			parent::OnBeforeItemUpdate($event);
+
+			/** @var ThemeItem $object */
+			$object = $event->getObject();
+
+			if ( $object->GetDBField('StylesheetFile') && !$object->getStylesheetFile() ) {
+				$object->SetError('StylesheetFile', 'not_found');
+			}
+		}
+
+		/**
 		 * Set's primary theme (when checkbox used on editing form)
 		 *
 		 * @param kEvent $event