Solution : https://service.sap.com/sap/support/notes/435292 (SAP Service marketplace login required)
Key words : 
additional key words /sapapo/bopi, interactive backorder processing, source code correction, /sapapo/om 001, updated correctly, prerequisites notes 427533, program error, solution implement, import note 435343, implemented
Related Notes : 
       
| 446299 | BOP: Problems in the postprocessing | 
| 439745 | BOPI: New delivery schedules / scheduling | 
| 435343 | Backorder processing: Item does not exist | 
| 432509 | |
| 431807 | BOPI: Incorrect data transfer, COM error | 
| 427533 | Backorder processing: no update of the subitems | 
| 375193 | Backorder processing: Composite SAP note on posting |