If you ssh from an IA64 system running I64VMS OPENSSH V8.9-1E to an IA64 system running I64VMS OPENSSH V8.9-1G, you will be immediately disconnected. The log file on the system running I64VMS OPENSSH V8.9-1G will show: "userauth_pubkey: parse (null) vms_plus packet: incomplete message"
Systems running VSI I64VMS OPENSSH V8.9-1C don't have this problem. sftp from OpenSSH any version also appears to work OK.