SAP Message AJ668 - Billing doc. &1 (invoicing indicator incorrect in ERCHC) (start doc. &2)

Diagnosis
You want to remove billing document number &V2& from a billing order intransaction EA24.
The system has determined that billing document &V2& is involved in achain of adjustment reversals.
Billing document &V1& also belongs to this chain.
This document has inconsistent ERCHC data. There is no entry in theOPBEL field.
INCLUDE ISU_SAP OBJECT DOKU ID TX