Diagnosis
The field &v1& is blank.

System Response
It has been determined in part 1 of module ISU_BILLING_PREPARE_UPDATEthat field &v1& is not filled. Field &v1& must be filled in functionmodules ISU_BEGIN_OF_BILLING_PERIOD and ISU_PREVIOUS_BILL_SELECT.

Procedure
V1 must be determined in billing.