Checks and Derivations Not working in BRF+

Hi Experts,

I am having an scenario for applying the validation as well as derivation rule on some  fields in Material MDG through BRF+. I am just implementing a simple logic as Material type is not equal to "XYZ". if conditions satisfy than a Log message appear as " Enter XYZ in material Type". I followed step by step as mentioned in the below standard SAP MDG  document.

http://www.sdn.sap.com/irj/scn/go/portal/prtroot/docs/library/uuid/90243ca8-92af-2e10-b895-92533b2de0ce?QuickLink=index&overridelayout=true&57655641053848

But,after everythings got activated, when I am trying to create change request and giving some value other than" XYZ". It is not showing me any error message.

Could anyone please help me on this and let me know if I missed something.

Thanks in advance!!

Regards

Prateek Agarwal

P.S: Any useful answers will be rewarded.