Free – Users Unable to complete PayPal transaction

Hello,

We updated one of the sites we manage from version 1.6.9 to 1.8.2 and after the first user submitted a payment, we haven’t been able to collect anything since. PayPal will allow someone to get to the payment stage, then it provides an error about being unable to pay a duplicate invoice.

Looking through the transaction log, the last payment we received had an invoice marker of “undefined”. Looked at past invoices this has never been a marker and I think the root cause of the issues here.

I was able to copy the URL string from version 1.8.2 and version 1.6.9 and see that the string now includes some additional information.

1.6.9:
The string would stop here: &cmd=_xclick

1.8.2:
The string includes this: &cmd=_xclick&invoice=undefined&notify_url=(removed website url)%3Frest_route%3D%2Fpaypalipn%2Fv1%2Fcf7pp_production&Z3JncnB0=

I don’t see any setting to change this. Is there anything else that can be done to fix the issue? For the time being, I’ve reverted back to the 1.6.9 plugin as it’s the last stable code we had.

Thank you for your time on this!