Is dctwnpapp02 correct name of the client? Does it have correct DNS entry? Is this Domino in cluster? What environment variables and switches did you set for Lotus backup? What version of module did you use?

Yes the client name is correct. Yes, there is a DNS entry for the server name. This is not a Domino cluster. I used environment variables... NSR_CLIENT = DominoName NotesExecdirectory = Path, The Notes Module version is 2.2.1

Does the Domino Server instance name need a DNS entry?

Domino instance is not the client so it does not require DNS entry. With that in mind NSR_CLIENT should not be DominoName but rather client name pointing to the name used for client resource on the backup server.

Is dctwnpapp02 correct name of the client? Does it have correct DNS entry? Is this Domino in cluster? What environment variables and switches did you set for Lotus backup? What version of module did you use?