Solution : https://service.sap.com/sap/support/notes/382640 (SAP Service marketplace login required)
Key words : 
additional key words mb26, stock determination failed, transaction mb26, stock determination, goods issue, return code &, picking list, program error, mrp controller, selection criterion
Related Notes : 
       
| 822780 | MB26 confirmed reservation quantity not displayed | 
| 693369 | MB26 : Purchasing Group not displayed in the print list | 
| 542607 | MB26: List reservations partly incomplete |