Hi,
Am experiencing the same problem as well "This invoice has already been paid. For more information, please contact the merchant." with
Sandbox testing and am not able to update any "Profile" settings.
I have already deleted all the orders from the database. In fact, I've checked and its a new order number.
I did change the address_override = 0 because was encountering a "not ship to your location" error previously. It solved that issue,
does it affect?
Any solution to this?
Please advice.
Thank you.