Solution : https://service.sap.com/sap/support/notes/397288 (SAP Service marketplace login required)
Key words : 
additional key words mir7, generate runtime error table_invalid_index, runtime error occurs, form routine verteilung, prerequisites program error, transaction mir7, program sapleins, credit memo, purchase order, document parking
Related Notes : 
       
| 490574 | Composite SAP Note for stats program in purchasing SAPLEINS | 
| 483982 | Composite SAP Note for stats program in purchasing SAPLEINS |