Index: site/includes/path.inc
===================================================================
--- site/includes/path.inc	(revision 3)
+++ site/includes/path.inc	(revision )
@@ -122,7 +122,8 @@
         }
       }
       // If the alias has already been loaded, return it.
-      if (isset($cache['map'][$path_language][$path])) {
+
+      if (in_array($path_language, $cache['map']) && isset($cache['map'][$path_language][$path])) {
         return $cache['map'][$path_language][$path];
       }
       // Check the path whitelist, if the top_level part before the first /