Article Updated: 2 July 2015 (this is a permanent fix until we find out more information from Paypal). If you are running version 1.2.0 of OptimizeMember or above you do not need to apply this patch
Description of Issue
We recently became aware of an issue affecting Paypal orders on sites using OptimizeMember. The issue means that after an order is processed when using Paypal or OptimizeMember order buttons, the user will see an error page with the message:
Unable to Verify $_POST Vars Error
The user account setup processes will also not trigger due to this issue.
This issue is due to a recent change at Paypal which means they changed their IPN behaviour - they started refusing default WordPress User Agent strings sent by default WP_Http class.
This is not due to a bug with OptimizePress or OptimizeMember, it is 100% caused by changes at Paypal which are outside of our control
Solution for this Issue
We have now created a file which you can use to patch your OptimizeMember installations which have this issue (you should patch your site and then run a test transaction to ensure things are now working).
How To Patch Your Site:
Step 1: Click here to download the patch zip file - We recommend right-clicking the link and selecting "Save Link As or Download Linked File As" and select a location to save the file to on your computer
Step 2: Unzip/Extract the zip file on your computer - you should see a folder called "includes" appear
Step 3: Access your site via FTP and drag the "includes" folder into your Plugins/OptimizeMember folder
Step 4: You will be prompted to overwrite an existing file - this is ok - you can allow this to overwrite your existing file (this will overwrite one file to patch your install)
Step 5: Test your site again or have a friend test to ensure things are now working
If you prefer, you can extract the zip file, and upload the patched "utils-urls.inc.php" file directly to your OptimizeMember/includes/classes folder and overwrite the existing utils-urls.inc.php file there.
If you need more help:
If you need more help with this, or are having problems installing this patch, please contact our support team and include working WordPress administrator logins and FTP details for your site so we can patch your site for you.