If the recovery host is not at the same NetBackup release level as the backup host
Note the following about mixed-level backups and restores:
To restore from a NetBackup 7.x backup
To restore a virtual machine from a backup that a NetBackup 7.x backup host performed, a NetBackup 7.x recovery host is required. You cannot use a NetBackup 6.5.x recovery host to restore a virtual machine that was backed up by a NetBackup 7.x backup host.
To restore from a NetBackup 6.5.x backup
To restore a virtual machine (or selected files) from a NetBackup 6.5.x backup, the VMware Converter must be installed on the NetBackup recovery host. The recovery host can run NetBackup 6.5.x or 7.x. A staging area is required.