No unit is available for mounting the specified volume. The volume
already on the allocated unit is either permanently resident or reserved. It
could not be unmounted in order to mount the required volume, or the volume
cannot be unmounted because another DCB is open on that device.
Restriction: This topic applies only when the AppMaster Builder AddPack has been installed, and applies only to Windows platforms.
Resolution:
Inspect all INCLUDE statements for correct syntax and file
specifications and verify that the referenced file members exist. Check DD
statements for call libraries. Try rerunning the job. If the problem occurs
again contact the operator to check if there is a problem with the mounted
device.
