Solution : https://service.sap.com/sap/support/notes/1284106 (SAP Service marketplace login required)
Key words :
order-related billing, billing document processing, sales document processing, routine userexit_set_status_vbup_invoice introduces, routine userexit_set_status_vbup_invoice, routine userexit_set_status_vbup, form routine, business process, item status, specific customers
Related Notes :
1416067 | Syntax error in user exit implementation |
151533 | Partially billed third-party orders are completed |