SAP Message AH788 - Billing document &1: adjustment reversal indicator is inconsistent

Diagnosis
In the billing order for installation &v2& (scheduled billing date &v3&and billing transaction &v4&), billing document &v1& is marked ashaving been reversed for adjustment in the Doc.no. in adj. rev.field.
SPCANC = "X" has been specified in the ERCHC table for billing documentV1, but the opbel field is blank.
This represents an inconsistency because a billing document reversedfor adjustment must always be included in an invoicing.

System Response

Procedure
INCLUDE ISU_SAP OBJECT DOKU ID TX