Solution : https://service.sap.com/sap/support/notes/200188 (SAP Service marketplace login required)
Key words : 
additional key words purchasing organization, system generates message naa234, purchasing organization exists, message class mn, message class naa, debit-side settlement, settlement partner creditor, implement note 0327921 urgently, purchasing organization, assigned debitor
Related Notes : 
       
| 382749 | Org. data of an arrangement not copied during creation | 
| 327921 | Incorrect condition granter accepted in arrangmnt maintnance | 
| 184387 | Debtor w/ incorrct account group creates short dump | 
| 183379 | Composite SAP note subsequent settlement (Purchasing) 4.6 | 
| 152725 | Collective note: Subsequent settlement (Purch.) Release 4.5 | 
| 104668 | Collective note: Subsequent settlement (Purch.) Release 4.0 | 
| 40147 | Collective note: Subsequent settlement (Purch.) Release 3.0 |