s2Member v2.9.2 ( `Unable to verify POST vars` ) fixed.

[Jason Caldwell]

Hey guys. s2Member v2.9.2 has just been released, specifically to fix this elusive bug.

You can grab a copy of s2Member v2.9.2 here:
http://www.primothemes.com/post/s2membe ... th-paypal/
Or upgrade through the Plugins menu in your WP Dashboard.

= Changelog for v2.9.2 =
* Bug fix. A bug in the PayPal® Auto-Return routine for PDT ( Payment Data Transfer ) has been resolved. This bug was generating a message that read: `Unable to verify POST vars`. This was actually not a bug, but rather, a [limitation in PDT transmissions](https://www.x.com/message/34450#34450) from PayPal®. s2Member has been updated, with a work-around for this limitation. This bug was very elusive, because it was not affecting all PayPal® accounts. In some cases, it was only affecting PayPal® accounts opened after October 2009.

In cases where PDT ( Payment Data Transfer ) does NOT return any data, s2Member will handle this gracefully, by passing sole responsibility over to the IPN system. It appears that PayPal® is phasing out the PDT system with respect to subscriptions. Not completely yet, but it's continuing to move in that direction.

s2Member is designed to deal with all of these scenarios.
No PDT information is sent by PayPal, when:
1. There is a free trial in the first term.
2. Auto-Return/PDT is not enabled in your PP account.
3. Your PayPal account was established after Oct 2009.
4. A Subscription Modification occurs.

PayPal® accounts that were established after October 2009 are subject to this behavior more so than others. * In other words, this is a move in the right direction as far as PayPal® Standard integration goes. The PDT handler for s2Member is now capable of bowing out when it needs to. This makes s2Member more future-proof in its design.

In cases where s2Member does not receive any data from PayPal's PDT system, an alert will presented to the Customer, acknowledging their transaction, and notifying them that they'll need to check their email. Quote: "Thank You! ( please check your email )". - for an Email Confirmation sent immediately by s2Member.

Some additional transactional email notifications have been added to the IPN processor for s2Member, which are designed to handle these scenarios gracefully; and so the Customer is never left out in the cold.

[dfstorm2]

I'm getting this error all of a sudden. Plus i have the latest version of s2member installed. I have checked my s2member and pat pal settings and re-installed the s2member. i think this bug is back.

[NickFox]

I think I may know what's causing this error. In s2Member, your PayPal PDT Identity Token is not the correct one from Paypal. It happened to me when I went to sandbox mode and PayPal generated a different token than my regular PayPal account. It was a lucky find... )

Nick

[dfstorm]

Cheers for the reply nick. My id token is the same. Auto return is on and so is payment data transfer.

[tristanputman]

I too am currently experiencing this issue and have verified my settings in s2Member and at PayPal and everything matches up with the requirements stated in the documentation.

I have disabled any plugins that could possibly interfere.
I have reduced my .htaccess to the bare essentials.

IPN logging has been on since the very beginning, so I have that data.

My PayPal account is getting funded, the users are getting their notifications to setup accounts and login, but I received an email from PayPal that they would disable IPN on my account due to "IPNs sent to the your URL are failing".

Every Status listed in my IPN History at PayPal lists either "Retrying" or "Failed" at this point.

Thoughts?

[dfstorm]

Im starting again...gonna reinstall wordpress..reinstall s2member... going to run it as a bair bones installation to see if it works...(no postvars error and sending confirmation email successfully) If it doesn't im going to find another solution which will not involve s2member.

[tristanputman]

Please post back if that corrects the problem and everything starts working for you. My website is already in production, so a reinstall would be out of the question at this point, but I'm hoping to hear back from Jason on this soon and hopefully he will have some ideas on how to get it straightened out for us.

Update: Jason remoted into my server and narrowed it down to:

* Firewall configuration ( blocking PayPal IPs? )

* PHP configuration ( blocking POST vars from PayPal? )

* Apache configuration (redirecting certain User-Agents? )

I checked my server logs and it was showing a "500" internal server error. Got with my hosting provider and they believe that since the PayPal IPN does it's post-back using an empty User Agent and an empty Referrer, that it is tripping some security measures they have in place on the server.

I'm having my host whitelist the PayPal IP Addresses to attempt to solve the issue.
Here is a link to the PayPal IP Addresses:
https://cms.paypal.com/us/cgi-bin/?&cmd ... echecklist[*]

[Jason Caldwell]

Tristan. Thanks for server access so this could be tested,
and thank you for posting these additional details.

This is much appreciated!

[kittykatmeowmeow]

So, what fixed this?

[kittykatmeowmeow]

I fixed it. The only way that it works is if I generate a PayPal button through PayPal, not the s2member button generator. For some reason, when I would generate the button through the s2member PayPal Button options it would give me that error message. NOW, it doesn't!