Item 00001 for purchasing document && not selectable

Hi All,

Client upgraded to EHP 6 and to AFS 6.6;

In new system, In VF01 Save, we get Idoc (INVOIC) error "Item 00001 for purchasing document && not selectable"

PO does not have goods receipts (no entry in EKBE);

In parallel debug work (old & upgraded systems), I found the codes are slightly deferent in ME_READ_ITEM_INVOICE in upgraded system;

Appreciate your response if anyone found & resolved this issue (with note) please;

Thank you

Iver