After replacing or upgrading a Robotic Library or related hardware component, Backup Exec is unable to use the hardware device for backup and restore operations.
Exact Error Message
"Robotic Library Error"
"Invalid Physical Library Identifier"
or "Invalid Physical Volume Library Argument" Backup device shows as "Offline" on the Devices Tab
For Backup Exec Version 9.x and 10.x:
Recreate the tape drive or autoloader in Backup Exec for Windows Servers. The drive or tape library must be first disabled and then deleted from the Devices tab in Backup Exec. Restart the Backup Exec Services after deleting the devices. Choose to Stop and then Start all services from the Tools | Backup Exec Services Manager window. (Choose Restart Services in Backup Exec 10.0 or later.)
Also see this related document at Backup Exec's web portal:
How to recreate tape drives and autoloaders in Backup Exec for Windows Servers