Physical Volume Library Drive or Robot paused, offline, or disabled

Suggest you to install the latest device drivers from the following link:
http://support.veritas.com/docs/275676

Reconfigure the device in Bsckup Exec:
1. From Backup Exec | Devices Right Click the device/library | Properties | Uncheck “Enable device for backup Exec” Right click and delete the device.
2. Power cycle the device and the server
3. From :Program FilesVERITASBackup ExecNT
4. Run tapeinst.exe
5. Install Veritas tape drivers 275676
6. Check the results.

Article written by MyComputerAid.com