It depends if the coding of the original AP was correct.
If it was
You can enter a "paid" invoice using a negative qty to reverse the original.(which will NOT post to the GL)
Then re-enter the invoice, attach it to the PO, and also change the status to paid.
This will fix the PO.

If the coding was wrong on the original invoice:
Enter the new invoice, attach it to the PO.
Enter a credit to completely reverse the original invoice.
You can apply the credit to the new positive invoice using the reference field (please read Sage help)
But this cannot be reversed so be careful.

OR
Set them both to pay on the next check, since they cancel each other out, it will have no affect on the check.

Thanks Char,
I notice that the PO does not update the amount received to date and needed to manually enter it in 6-6-1
Aloha,
~j

Hello,

There is issue in the" To DATE " on the Purchase order ! 

. There is an issue with some Purchase orders with the remaining balance. The relevant invoice has already been booked (picked the Quantity of the correct line of PO ) base on the vender sent the items . However, the Quantity did not update under the “To Date “ column In the Purchase order.

The received items in PO show as (0) then. 

Can you please advice ?