IIUB128E IMS MANAGEMENT OF ACB WITH UNREGISTERED CATALOG IS NOT SUPPORTED

Explanation
IMS-managed ACBs is enabled but the IMS catalog database is not
                registered to the DBRC RECON data sets. IMS Index Builder does not support IMS catalogs that are not registered to the
                DBRC RECON data sets.

System action
Processing stops.

User response
Register the IMS catalog databases to DBRC or disable IMS management of ACBs, then rerun the IMS Index Builder job.