Hi Andreas,
It is not the case that you are assuming.
I just mentioned that we assigned the T-code access (ES22) to the UCES reference user which solved the issue but that doesn't diminish the valuable inputs that you provided in your replies!!!
Anyways, I am marking your reply as the correct answer as it deserves it.
Thanks a lot once again and wish you a happy new year in advance 
BR,
Anurag