diff --git a/xCAT-server/lib/xcat/plugins/esx.pm b/xCAT-server/lib/xcat/plugins/esx.pm
index ce8d99366..884d88b92 100644
--- a/xCAT-server/lib/xcat/plugins/esx.pm
+++ b/xCAT-server/lib/xcat/plugins/esx.pm
@@ -98,7 +98,7 @@ sub preprocess_request {
 	}
     xCAT::Common::usage_noderange($request,$callback);
 
-        if ($request->{_xcatpreprocessed}->[0] == 1) { return [$request]; } 
+        if ($request->{_xcatpreprocessed} and $request->{_xcatpreprocessed}->[0] == 1) { return [$request]; } 
          # exit if preprocesses
 	my @requests;