Hi Vishwanath,
As per your screenshots, the problem lies in the SSO connection of your Portal system with the backend system.
Please ensure if all the steps have been properly followed to establish SSO between Portal and SAP ECC system.
Just a quick question, do you have different User Ids in Portal and SAP ECC systems for the same user?
If not, you can use SSO using SAP Logon Tickets. In this way, you won't have to maintain user mapping for each user.
BR,
Anurag
