Solution : https://service.sap.com/sap/support/notes/386249 (SAP Service marketplace login required)
Key words :
~ftp/specific/isafs/v10d/note, additional key words eban, prerequisites program error solution, neagtive purchase requistions, negative purchase requisitions, negative quantity
Related Notes :
| 394612 | AFS V1.0D2 Fixpack #9 including HP/LCP 59-73 |