Thanks for the quick response. I do intend to migrate, but that's going to take some time and I'd like a working payment module in the meantime. I've been using the PayPal Standard module. It's in /includes/modules/payment/paypal_standard.php. There is no "paypal" directory there. I tried adding one with the crt file, but no go. Also no go with the crt in the payment directory. In fact, I can't find a previous one anywhere.
Is there a 2.3.4 to Phoenix upgrade documentation?
Thanks.