diff --git a/xCAT-server-2.0/lib/xcat/plugins/blade.pm b/xCAT-server-2.0/lib/xcat/plugins/blade.pm
index 80f2fff71..9c66ce120 100644
--- a/xCAT-server-2.0/lib/xcat/plugins/blade.pm
+++ b/xCAT-server-2.0/lib/xcat/plugins/blade.pm
@@ -1195,10 +1195,13 @@ sub process_request {
   my $noderange = $request->{node};
   my $command = $request->{command}->[0];
   my @exargs;
+  unless ($command) {
+     return; #Empty request
+  }
   unless ($noderange or $command eq "findme") {
     my $usage_string=xCAT::Usage->getUsage($command);
     if ($usage_string) {
-      $callback->({data=>$usage_string});
+      $callback->({data=>[$usage_string]});
       $request = {};
     }
     return;
diff --git a/xCAT-server-2.0/lib/xcat/plugins/ipmi.pm b/xCAT-server-2.0/lib/xcat/plugins/ipmi.pm
index ce6df590b..6f91b8458 100644
--- a/xCAT-server-2.0/lib/xcat/plugins/ipmi.pm
+++ b/xCAT-server-2.0/lib/xcat/plugins/ipmi.pm
@@ -4577,7 +4577,7 @@ sub process_request {
     unless ($noderange) {
         my $usage_string=xCAT::Usage->getUsage($command);
         if ($usage_string) {
-            $callback->({data=>$usage_string});
+            $callback->({data=>[$usage_string]});
             $request = {};
         }
         return;