Solution : https://service.sap.com/sap/support/notes/202461 (SAP Service marketplace login required)
Key words :
post collective billing documents online, additional key words vf04, billing due list, billing documents, system calls, branch back, 'save' pushbutton, screen sequence, program error, simulation mode
Related Notes :
337684 | VF24 - incorr select w/ collective bill doc./online |
139890 | Collective note : Online processing VF04/VF06 |