Solution : https://service.sap.com/sap/support/notes/92486 (SAP Service marketplace login required)
Key words :
additional key words zuonr, object component 'field list', field bseg-zuonr, purchase order assigned, field 'allocation number', attribute 'modification group 2', message 00055 'required entry, required field, direct postings, program error
Related Notes :
| 94932 | MR08: Business area in the vendor line item |
| 38597 | MR08, MR44, MRKO; Field 'Allocation number' (ZUONR) |