Solution : https://service.sap.com/sap/support/notes/523661 (SAP Service marketplace login required)
Key words :
error message /sapapo/mpit 001 stating, select 'long text'enter, internal document number <posguid>, external document/item number, enter /sapapo/atp_bop, /sapapo/bop_resultbackorder processing, diagnosis item _v1_, source code corrections, call transaction se91, backorder processing terminates
Related Notes :
| 375193 | Backorder processing: Composite SAP note on posting |