UseOneAsMany Function Not Working

Hi Experts,

I have tried the example from the below blog: **************** - Implementation of Node functions

I have changed the context level as mentioned in the blog. I have changed the Plant Context Level to Mt_Sender for both MatNo and MatDesc while Mapping on target Side. Remaining i have Mapped normal field to field from Source to Target. When i am checking the Message Mapping it is throwing the Error as mentioned below:

Source Structure:

<?xml version="1.0" encoding="UTF-8"?>

<ns0:MT_Sender xmlns:ns0="http://UseOneAsManyExample">

   <Header>

      <MatNo>MatNo</MatNo>

      <MatDesc>MatDesc</MatDesc>

   </Header>

   <Item>

      <MatNo>MatNo1</MatNo>

      <ItemNo>ItemNo1</ItemNo>

      <MatGroup>MatGroup1</MatGroup>

      <Mattype>Mattype1</Mattype>

      <Plant>Plant1</Plant>

   </Item>

   <Item>

      <MatNo>MatNo2</MatNo>

      <ItemNo>ItemNo2</ItemNo>

      <MatGroup>MatGroup2</MatGroup>

      <Mattype>Mattype2</Mattype>

      <Plant>Plant2</Plant>

   </Item>

</ns0:MT_Sender>

Required Target Structure should be as mentioned in the blog. This is a very basic example, but i am not getting the Output. Please check and let me know where i am going wrong in mapping.

Regards,

GIRIDHAR