Solution : https://service.sap.com/sap/support/notes/520755 (SAP Service marketplace login required)
Key words :
symptom error >2460'internal error, budget billing amount occur, budget billing amount, due date combination, program error, terms ea10, lower item, solution implement, program correction, fkk_pyform_insert
Related Notes :
| 500762 | INV: Next budget billing amt without payment form reference |