I am using the SIM Payment Gateway with Cartthrob but the response/receipt URL is not displaying after submitting the payment on authorize.net. Interestingly, I got it to work previously after adjusting the name of my system directory in the extload.php file. But now I get the following error message:

An error occurred while trying to report this transaction to the merchant. An e-mail has been sent to the merchant informing them of the error. The following is the result of the attempt to charge your credit card.

This transaction has been approved.

It is advisable for you to contact the merchant to verify that you will receive the product or service.

I recently updated to CT version 2.2.2 and now 2.2.91 so that could potentially be related. I did make sure to keep the correct system path in extload.php though.

Any ideas where I might have gone wrong?

  • Did you contact SIM Payment Gateway to what the error is?
    – Anna_MediaGirl
    Feb 14, 2013 at 2:10
  • No, but I was reading this documentation from Authorize.net which addresses this specifically (support.authorize.net/authkb/…). Looks like Cartthrob is supposed to respond to a post request but so far I haven't figured out why it hasn't.
    – user1011
    Feb 14, 2013 at 12:10
  • I would first contact SIM to see what error is actually getting reported on their end. That will help you track things backward.
    – Anna_MediaGirl
    Feb 14, 2013 at 15:31

1 Answer 1


No changes were made to SIM between 2.2.2 and 2.2.9x. ExpressionEngine updated their secure forms system recently in version 2.5.5 which has wreaked some havoc with items that redirect. 2.2.9 should have fixed this, but I haven't tested with this specific gateway.

Though you said you've maintained the system folder location in extload, I'd double check it to make sure you haven't overwritten it with the old location.

The other thing you may want to check is that the response / receipt URL is devoid of Javascript and insecure includes (including css files, images, etc). SIM generally fails templates that contain insecurely loaded content and JS.

Lastly, if you have a return variable in the checkout form, make sure it's just set to something like this: return="template_group/template" rather than a full URL. Some servers may end up choking when generating return locations if they're input as full URLs.

  • Thank you very much for your help! That was very informative. I actually ended up getting the dpm method working (instead of sim). Turns out I made the simple mistake of selecting development mode instead of test mode (which we were using). I didn't check it but changing that probably would have fixed my problem with the sim method.
    – user1011
    Feb 21, 2013 at 17:02

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