It seems that NW expects the volumes in other devices.
Most likely your device list for that pool does not fit.

The issue is that you can specify pools for certain devices (Media Pools > 
Selection Criteria tab > Target Device - Devices).
If you do not specify the right devices, NW will just assume that the volumes 
mut be mounted on other devices.

+----------------------------------------------------------------------
|This was sent by carsten_reinfeld AT avus-cr DOT de via Backup Central.
|Forward SPAM to abuse AT backupcentral DOT com.
+----------------------------------------------------------------------