Hi Ramkumar,
Thank you so much!
I added Mapwithdefault to all the mandatory fields, it works now.
Got this 
for the message, but the data mapping seems not right: at the very beginning of the data XML as in the first image, I have all the data, but in message mapping I seem lost quite few data fields as in the second image.
I am just wondering where in the mapping got the problem:
First image:
Second Image:
