I am trying to get my PayPal IPN Listener to work on my Live environment, it works on Staging perfectly and the issue is something to do with the web.config file:
(http://pastebin.com/B8YhJEZK)
I am using "https://developer.paypal.com/us/cgi-bin/devscr" and the Instant Payment Notification (IPN) simulator to test the web service however I am getting the following:
"IPN delivery failed. HTTP error code 500: Internal Server Error"