Index: /branches/version-2_12-multilang/html/install/index.php
===================================================================
--- /branches/version-2_12-multilang/html/install/index.php	(revision 22278)
+++ /branches/version-2_12-multilang/html/install/index.php	(revision 22349)
@@ -203,5 +203,7 @@
             //dummy以外は削除
             if ($file_name != 'dummy'){
-                unlink($cache_dir . $file_name);
+                if (is_file($cache_dir . $file_name)) {
+                    unlink($cache_dir . $file_name);
+                }
             }
         }