Apologies for resurrecting such an old question; this is the only reference to that warning message I've found online.
I can replicate this warning when trying to add nodes to an on-premises HPC Pack 2019 cluster, where the nodes belong to a subdomain. - i.e., my domain name is called "mydomain.local", but the head-node and compute nodes are being added to a sub-domain "hpc.mydomain.local". I get the warning message reported above, even though the nodes are already joined to the domain and work perfectly. C:\Windows\Temp\HPCSetupLogs contains the following:-
10:45:17.773 - [CheckRule] Checking rule Domain -- Check if the computer belongs to a domain.
10:45:17.804 - [DomainRelationshipVerified] NTAccount (hpc.mydomain.local\node-003$) translation failed with exception: System.Security.Principal.IdentityNotMappedException: Some or all identity references could not be translated.
at System.Security.Principal.NTAccount.Translate(IdentityReferenceCollection sourceAccounts, Type targetType, Boolean forceSuccess)
at System.Security.Principal.NTAccount.Translate(Type targetType)
So it looks like the setup is assuming the domain name is "hpc.mydomain.local" rather than just "mydomain.local", and then throws the warning.
More info - my head node is running Win Server 2022, and the nodes being added above are Windows 10 with the OS set up, already joined to the domain, running \hn\REMINST\setup to add them as workstation nodes.
On the next page, I have to manually type in the full headnode name (hn.hpc.mydomain.local) rather than choosing it from the dropdown menu as I normally would, but after that it appears to add successfully to the cluster. Hoping that we won't run into any problems later though.