Tape vaulting task could not find useable volume

c:\Program Files\Quantum\DATASTOR Shield\Server>vlm volume status -volume mon005l6

Volume Library Manager Command Tool (64-bit) Version 9.0.1800.1
Copyright (C) 2005-2018 Data Storage Group, Inc. All rights reserved.

 Name............... MON005L6 *Assigned* *No Barcode* ~Appendable~
 Description........
 VolumeTag.......... MON005L6
 ...
 VolumeType......... *Tape*
 Enabled............ FALSE

 
The if the output indicates Enabled=FALSE run a property command to set Enabled=TRUE.

vlm volume property -volume [volume name] -prop Enabled=TRUE
See example:
c:\Program Files\Quantum\DATASTOR Shield\Server>vlm volume property -volume mon0
05l6 -prop Enabled=TRUE

Then, run the status command again and review the output to confirm that the Enabled status is TRUE.