Solution : https://service.sap.com/sap/support/notes/81470 (SAP Service marketplace login required)
Key words :
additional key words invoice creation, print program saplnfr1, document number entry, invoice printout, document number, properly posted, financial accounting, table vbrk, vbrk-belnr, creating invoices
Related Notes :
| 48260 | IS-H: Missing FI document number for invoice |