Hi Manish,
These issues generally happens only in one system as Org structure is defined in each system. You can try some more things as below:-
- Go to USERS_GEN and check the consistency of that particular ID or node.
- Try to Repair and Sync from USERS_GEN.
Some similar post to your problem as as below:-
Issue with PO in SRM Portal - Object or set with GUID 0000 does not exist
Object or set with GUID 00000000000000000000000000000000 does not exist.
Also check SAP Note 1762735. May be it will give you some link.
Thanks
Siddarth