I have used chronoform 5 in joomla site and the payment is getting failed. When I enabled log error in paypal it returned following information.
The PayPal API has returned an error!
Ack:
Correlation ID:
Version:
Error Number:
Short Message:
Long Message:
Joomla : 3.7.5
ChronoForm: 5
Payment Processors: PayPal Pro
The payment transaction was a failure due to site lacking https protocol.
PayPal now requires an https connection. Since the payment is handled within the site.