Hi,
Refer to the following link:
"An unknown error occurred within the NDMP subsystem" or "Selection of the item is disabled. You are not authorized to access this item, a license key for Backup Exec Remote Agent for Windows Servers is not installed on this machine, or the Remote Agent is old or incompatible" is received when attempting to select a local or remote system.
http://support.veritas.com/docs/262928
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