How to debug PayPal IPN issue?

Question

Environment: Joomla: 3.4.4, CiviCRM: 4.6.2, PHP: 5.4.45, MySQL: 5.5.42-37.1 HTTP only, no HTTPS, On Shared Hosting at HostGator

The site is a few months old, and we've had 30-50(?) online payments (member dues, events, donate) via PayPal Standard, but all of the transactions remain "Pending".

I've followed and double checked "Configure Paypal to Talk to CiviCRM" here ... http://wiki.civicrm.org/confluence/display/CRMDOC/PayPal+Website+Payments+Standard+and+Recurring+Contributions

• IPN is Enabled
• IPN points the sites home page, including "http://" (http://my-site.org) ... (worth noting the home page is managed by Joomla, not CiviCRM, but since the url is a "place holder' it does not make any difference I assume)
• Auto Return: On
• Payment Data Transfer: Off

I enabled the Joomla Redirect Component to catch any 404's, assume some how the IPN URL is wrong. But there have been no IPN related 404s in there. This makes me think the issue is either 1) the link back from the IPN is valid, but not being processed, or 2) the IPN never reaches the site.

I have enabled Logging in the CiviCRM Admin, but where should I look for IPN details? There are many log_civicrm_% tables in mysql, but none seem to log IPN details.

I assume PayPal IPN Simulator might give me some clues, but how do I construct a test URL?

Answer 1

I kept pulling my hair out until we migrated to paypal pro (with it's own set of issues :)) but a couple of things to look at:

1. Check apache error log,
2. Paypal has a log that shows details of all IPN calls to server.
3. Make sure you have correct URL for http vs. https
4. Check civicrm log files in files/civicrm/ConfigandLog
5. Make sure firewall rules (and especially modsecurity) are letting things post
6. Don't know about joomla but in drupal, I always need to disable IDS (Intrusion Detection) for anon users and it often triggers false positives.

Answer 2

I found and fixed the problem. In this case the root cause was the site was moved at go-live. Interesting to note the CiviCRM Admin panels and CiviCRM frontend pages all worked fine.

I found IPN listeners in here: /administrator/components/com_civicrm/civicrm/extern/

I pinged the listeners URLs like:

http://my-site.org/administrator/components/com_civicrm/civicrm/extern/ipn.php

And got this error:

Could not load the settings file at: /home2/my-site/public_html/joomla3/administrator/components/com_civicrm/civicrm.settings.php

/joomla3/ was the development subdomain.