I have had a very happy successful Moodle site running for 7 years now. Suddenly over the last couple of months my users have started to get the "thank you for your payment..." message? I checked my PayPal settings and IPN was not actually turned on but then it never had been previously as this was not something I needed to set up when I created it all those years ago. As I say everything had been working fine, we have had many self enrollments using PayPal.
I have tried everything suggested above and still not getting anywhere. Still getting the same message.
I will admit I have not upgraded Moodle to the latest version as I was reluctant to do this. So I am on Moodle 2.0.3. The reason for the reluctance was that last time I upgraded I had to redo every link to every image in every course so I have hesitated to upgrade.
Has anyone managed to work out what is going on here? If upgrading will fix it could someone let me know as I will do it if this will fix it?