I've been using CMGroupBuying for several years. I recently offered a deal that was very popular and caused more traffic than usual, and something went terribly wrong with the process. To begin, I had set the maximum number that buyers could purchase to three, but the component was allowing buyers to put in any number they wished. My webmaster changed the code to limit the drop-down box to three max.
But then I started hearing from buyers who clicked on the deal and saw the information fields pre-filled with the names and addresses for previous buyers. These purchasers reported to me that they tried to change erase the fields and put in their own information but could not. PayPal processed the transaction -- and took their money -- but the component assigned the same order number as the previous buyer or an order number one or two higher -- in either case, the buyer did not receive a link to the certificate.
Needless to say this caused a great deal of distress, not to mention damage to my reputation as a merchant. Have you encountered this problem before, and can it be fixed?
My version of CMgroup is 2.8.0.
Thank you. Scott

Hi Scott,

I haven't seen any problems like this. If you have enabled cache of Joomla or any other cache extension, you can try to disable them to see if the problem is gone.

CMGroupBuying asks Joomla to not cache it by default, you can check your components/com_cmgroupbuying/controller.php to ensure that $cachable is not set to "true". However, third party cache extensions may try to cache everything.

If you use services like Cloudflare, you can exclude your shopping cart or any pages which stores user's information to see if it helps. If your server or hosting provider has any kind of caching, you may want to disable them to see if there is any differences.

Regards,
Hung

Hung,
My webmaster confirmed that we use Cloudflare. He made the changes you suggested and we relaunched the deal. I have not gotten any complaints that people are seeing the contact information of previous buyers pre-filled in the form.

However, a large number of buyers are not getting the links to their certificates (even after checking spam folders). And about a third of the orders are not automatically converting to "paid" when cleared by PayPal. Can you offer any guidance for these problems?

Thank you

Hi Scott,

You can check the log file of PayPal plugin in your Joomla's log folder to see if PayPal sent the callbacks for the recent transactions to your site. If it did, you can see the transactions in the log file together with the reason why they were invalid. I don't know how you turned off Cloudfare but PayPal requires HTTPS, so if your site doesn't use HTTPS PayPal doesn't send callbacks to your site.

Regards,
Hung