@Anusha_sunkadh Thank you.
It looks like this was an effect of a misconfiguration while looking for the UIN in my other post. After fixing that and re-starting regproc and regclient modules, there was no longer any error.
I just had to register the person again because the previous data is stuck/frozen in uploading status. I tried several times to select and upload it but no means to upload it since the upload button doesn’t show (top right corner)
Well that is another issue I will set aside for now, since I can now continue what I was doing in my post Help in the Registration Process - UIN - Email notification
We can consider this issue closed.