Solution : https://service.sap.com/sap/support/notes/489310 (SAP Service marketplace login required)
Key words :
support package level, purchase order header, tab title exporting, function module exit_saplmewp_002, user exit exit_saplmewp_002, function module bapi_po_create, customer function 002, customer exit, exit_saplmewp_002 reason, symptom caution
Related Notes :
439755 | BAPI_PO_CREATE: EXIT_SAPLMEWP_002 incomplete |
323152 | Enjoy BAPI: Implementation of customer enhancements |
160706 | No exceptions in BAPI_PO_CREATE |