Solution : https://service.sap.com/sap/support/notes/324694 (SAP Service marketplace login required)
Key words :
multiple account assignment screen reports, multiple account assignment screen, additional key words me21n, enjoy purchase requisition, output error messages, enjoy purchase order, purchase requisition, error messages, purchase order, transaction me21n
Related Notes :
310154 | ME21N/ME51N: Customer-specific check, generating error log |