diff --git a/leshan-server-demo/src/main/java/org/eclipse/leshan/server/demo/servlet/json/ResponseSerializer.java b/leshan-server-demo/src/main/java/org/eclipse/leshan/server/demo/servlet/json/ResponseSerializer.java
index 539483dcc8..cd01cddc1b 100644
--- a/leshan-server-demo/src/main/java/org/eclipse/leshan/server/demo/servlet/json/ResponseSerializer.java
+++ b/leshan-server-demo/src/main/java/org/eclipse/leshan/server/demo/servlet/json/ResponseSerializer.java
@@ -47,6 +47,8 @@ public JsonElement serialize(LwM2mResponse src, Type typeOfSrc, JsonSerializatio
                 element.add("location", context.serialize(((CreateResponse) src).getLocation()));
             }
         }
+        if (src.isFailure() && src.getErrorMessage() != null && !src.getErrorMessage().isEmpty())
+            element.addProperty("errormessage", src.getErrorMessage());
 
         return element;
     }
diff --git a/leshan-server-demo/src/main/resources/webapp/js/helper-services.js b/leshan-server-demo/src/main/resources/webapp/js/helper-services.js
index 3c8f359f5a..bc63cb17a2 100644
--- a/leshan-server-demo/src/main/resources/webapp/js/helper-services.js
+++ b/leshan-server-demo/src/main/resources/webapp/js/helper-services.js
@@ -20,23 +20,26 @@ myModule.factory('helper', ["$filter", function($filter) {
   var serviceInstance = {};
   
   serviceInstance.handleResponse = function (response, lwm2mNode, successCallback) {
-	  lwm2mNode.date = new Date();
+      lwm2mNode.date = new Date();
       var formattedDate = $filter('date')(lwm2mNode.date, 'HH:mm:ss.sss');
       if (!response.valid){
-    	  lwm2mNode.status = "INVALID";  
+          lwm2mNode.status = "INVALID";  
       }else if (response.success){
-    	  lwm2mNode.status = "SUCCESS";
+          lwm2mNode.status = "SUCCESS";
       }else {
-    	  lwm2mNode.status = "ERROR";
+          lwm2mNode.status = "ERROR";
       }
-      
+
       if (response.valid)
-    	  lwm2mNode.tooltip = formattedDate + "<br/>" + response.status ;
+          lwm2mNode.tooltip = formattedDate + "<br/>" + response.status ;
       else
-    	  lwm2mNode.tooltip = formattedDate + "<br/> Not LWM2M Code <br/>" + response.status;
+          lwm2mNode.tooltip = formattedDate + "<br/> Not LWM2M Code <br/>" + response.status;
       
+      if (response.errormessage)
+          lwm2mNode.tooltip = lwm2mNode.tooltip + "<br/>" + response.errormessage;
+
       if (successCallback && response.success) {
-    	  successCallback(formattedDate);
+          successCallback(formattedDate);
       }
   };
   return serviceInstance;