Hi Eng,
Thanks for your reply.
Ok, Today we will be transporting changes again, If it won't work I will discuss about SAP Note with Basis.
>>>>>Does the mapping open successfully in your Dev system?
Yes, it is.
>>>>>Compare also the versions of your source and target structure between Dev and Quality system. Make sure the structures are the same in both system.
I have compared versions of source and target structure. Both are identical.