Version 5.0.6

applications/core/setup/upg_5000015/upgrade.php

@@ -61,7 +61,15 @@ class Upgrade
 				], [ 'id=?', $root['id'] ] );
 
 				/* Create the language string */
-				$class = 'IPS\\' . $root['app'] . '\extensions\core\FrontNavigation\\' . $root['extension'];
+				try
+				{
+					$class = Application::getExtensionClass( $root['app'], 'FrontNavigation', $root['extension'] );
+				}
+				catch( OutOfRangeException $e )
+				{
+					continue;
+				}
+
 				if( in_array( $root['app'], array_keys( Application::enabledApplications() ) ) and class_exists( $class ) )
 				{
 					/* @var FrontNavigation\FrontNavigationAbstract $class */