I have come across a case where an invoice generated from a PO delivery ended up having negative volume. It was not possible to open the invoice via VF03 , nor via VF02 to correct the incorrect volume value. I also tried to cancel the invoice via VF1...

The background delivery creation from transaction VL10B calls the parallel processing which cannot be debugged directly. Even if breakpoints are kept in all relevant user exits , the debugger wont be called.Consider the below Purchase Order in ME23N ...

VF04 is the transaction used to display the billing due list. It displays only those deliveries which are posted or whose PGI is complete. If we need deliveries which are not posted also to appear in the output list, we have explore enhancement user ...