Index: ChecksStep.class.php
===================================================================
--- ChecksStep.class.php	(revision 145)
+++ ChecksStep.class.php	(working copy)
@@ -77,6 +77,12 @@
         foreach ($this->check_is_writable as $relative_folder_path) {
           $check_this = INSTALLATION_PATH . $relative_folder_path;
           
+          if (!file_exists($check_this)) {
+            $this->addToChecklist("$relative_folder_path does not exist", false);
+            $all_ok = false;
+            continue;
+          }
+
           $is_writable = false;
           if (is_file($check_this)) {
             $is_writable = file_is_writable($check_this);