DNA-1006-00-E VOL mount prob rerun

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 of your INCLUDE statements for correct syntax and file specifications and verify that the referenced file members exist. Also 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.