I'm using s2member Pro and am having a problem with payment to paypal. I'm getting the following message (and have read all the other threads with this message but not found a solution yet):
"ERROR: Unable to verify $_POST vars.
Please contact Support for assistance.
This is most likely related to an invalid configuration of s2Member, or a problem with server compatibility. If you are the site owner, and you're absolutely SURE that your configuration is valid, you may want to run some tests on your server, just to be sure $_POST variables are populated, and that your server is able to connect/communicate with your Payment Gateway over an HTTPS connection.
s2Member uses the WP_Http class for remote connections; which will try to use cURL first, and then fall back on the FOPEN method when cURL is not available. On a Windows® server, you may have to disable your cURL extension; and instead, set allow_url_fopen = yes in your php.ini file. The cURL extension (usually) does NOT support SSL connections on a Windows® server.
Please see this thread for details regarding the ideal server configuration for s2Member."
I have checked out the thread it mentions, uploaded the related files and got the following messages:
for - curl-test-https-paypal.php: "Test succeeded Lookin' good here. Your cURL extension is functioning properly, with SSL enabled too."
and for - fopen-test-https-paypal.php: "Test succeeded Lookin' good here."
What's odd is that I have been using s2member in an addon domain on the same server for over a year, with great success. Is there any other configuration I may have overlooked that could cause this error?
Or could it be something I need to configure at Paypal?
Thanks in advance for any help you can offer
-sam