Authorize.net AIM on OC 1.5.6.4 - CC transaction processes but downloads not available after purchase

This is my third year using the same OpenCart installation and this is the first time we've had this problem. The cart was working fine. My customer changed payment processors, but is still going through Authorize.net for the gateway. Authorize.net's email was forwarded to me and I set up a new account and generated a new Transaction Key, per their instructions. Input the new LoginID and Transaction Key into my OC Payments module. We performed tests and everything was working as expected. Then I turned from Test Mode to Live (yes, in both OC and Authorize.net). Now...

When a customer makes a credit card payment, the transaction processes through Authorize.net AIM, just as it should, and OC gives the customer a message that their transaction has completed successfully. BUT, the customer never receives a receipt from OpenCart and their Downloads (which is what they are purchasing) are not available. Furthermore, there is NO RECORD of their transaction in OpenCart (Sales, Orders). This is happening ONLY on credit card purchases. Most customers have a download coupon they purchased earlier and are processing through Free Checkout. That is working just fine. It's only the credit card payments that are messed up.

I've been racking my brain over this for days. The cart is live and we can't shut it down at this point. The money is in Authorize.net so my clients are fulfilling the orders manually, but this is not an acceptable long-term solution.

Any ideas, Anyone?

Which plugin are you using?

Did you take a look at this thread:

https://community.developer.authorize.n ... td-p/37181

Thank you for your reply. Under Extensions > Payments I am using the Authorize.net AIM Plugin. It's the standard that came with my version of OC and it has been working fine up until now. Honestly, I didn't know there was anything else until I read some posts in the forum where people were using a different plugin.

Thanks for the link to the Integration and Testing thread. I had not found that one but I read through it and I will try what it suggests. I hope it works because I have another of these coming up in a couple of weeks for the same customer of mine. Fingers crossed!

There were a few fixes to the Authorize.net AIM payment module since 1.5.x. Some of these may help.

https://github.com/opencart/opencart/co ... aded3b1d8a
https://github.com/opencart/opencart/co ... aded3b1d8a
https://github.com/opencart/opencart/co ... 69df92e519
https://github.com/opencart/opencart/issues/814
https://github.com/opencart/opencart/pull/1317