Check the NetBackup Problems report for the cause of the error. To obtain detailed troubleshooting information, create an admin debug log directory and retry the operation. Check the resulting debug log.

If the error was encountered during duplication of backups, check the duplication progress log to help determine the root cause of the problem.

If a Vault job encountered the error responsible for the duplication, check the duplicate.log files in your sidxxx directories to determine the root cause:

UNIX and Linux: 
/usr/openv/netbackup/vault/sessions/vault_name/sidxxx
Windows: 
install_path\NetBackup\vault\sessions\vault_name\sidxxx

(where xxx is the session ID)