Unable to verify $_POST vars.

S2member is promoting new users when they purchase a membership but its not demoting using when their subscription ends, expires or is cancelled.

To help trouble shoot the problem I’ve turned logging on.

I receive this message in paypal-ipn.log

LOG ENTRY: Thu Apr 25th, 2013 @ precisely 12:29 am UTC
PHP v5.3.3 :: WordPress® v3.5.1 :: s2Member® v130406 :: s2Member® Pro v130406
Memory 55.44 MB :: Real Memory 55.75 MB :: Peak Memory 55.51 MB :: Real Peak Memory 55.75 MB
coolproxies.com/?s2member_paypal_notify=1
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.64 Safari/537.31
array (
‘s2member_log’ =>
array (
0 => ‘Unable to verify $_POST vars. This is most likely related to an invalid configuration of s2Member, or a problem with server compatibility.’,
1 => ‘Please see this KB article: `http://www.s2member.com/kb/server-scanner/`. We suggest that you run the s2Member® Server Scanner.’,
2 => ‘array (
‘s2member_paypal_notify’ => ‘1’,

I’ve installed server-scanner and I get this error.

ERROR] cURL Extension / Or fopen() URL
One or more HTTP connection tests failed against localhost.
Cannot connect to self over HTTP — possible DNS resolution issue.
Can’t connect to: http://coolproxies.com

In order to run s2Member®, your installation of PHP needs one of the following…
• Either the cURL extension for remote communication via PHP (plus the OpenSSL extension for PHP).
• Or, set: allow_url_fopen = on in your php.ini file (and enable the OpenSSL extension for PHP).
Please consult with your web hosting company about this message. See also: WordPress recommended hosting platforms.

php-curl, libcurl and php-openssl are installed.
allow_url_fopen is set to = on

I’m not sure what to do next to get things working. Please help.

php-curl, libcurl and php-openssl are installed.
allow_url_fopen is set to = on

But for some reason the tests are not passing in the server scanner, so it’s not working for s2Member either. You need those tests to pass.

Have you contacted your webhost about those messages so they help you? It’s a server configuration thing.

Hi, Im the webhost, Its hosted on my local CentOS server that I use for my important websites. I’m pretty sure curl and openssl are working since other webapps also use those features but it still fails the test. Users are being upgraded when they subscribe but they are not being demoted when their subscription ends.

Is there any further help you can provide?

Hi, Im the webhost, Its hosted on my local CentOS server that I use for my important websites. I’m pretty sure curl and openssl are working since other webapps also use those features but it still fails the test. Users are being upgraded when they subscribe but they are not being demoted when their subscription ends.

The problem here is that s2Member needs to be able to connect back to itself via URL fopen or cUrl, and your hosting environment most likely prevents this from working for one reason or another.

Looks like I diagnosed the problem. My wordpress site uses the Quick Cache plugin, When we migrated the server over some of the directory permissions where not set correctly. Specifically the /wp-content/cache/ directory. Once I set the cache directory to writable it now passes all test including the CURL test. Hopefully this info will help someone else.

Great! Thanks for the update. I’m informing Jason so he can investigate it. :)