Authorize.Net (SIM) failing

I am trying to run a transaction from OpenCart for the first time, sending to Authorize.Net (SIM). I get this error message:

(13) The merchant login ID or password is invalid or the account is inactive.

My account is active. From reading Authorize.Net helps, it seems to be wanting my API Login ID.

However, when I edit Authorize.Net (SIM) characteristics in Extensions > Payments > Authorize.Net (SIM), I can enter Merchant ID, Transaction Key and MD5 Hash. But not API Login ID.

Where can I enter API Login ID? Or what am I missing in regards to communicating with Authorize.Net (SIM)?

Merchant ID = Login ID... it is just what they call the field.
The error simply means your account isn't valid... either you have a typo or you are using a dev account in live mode or a live account in dev mode

Thanks. I've updated the Merchant ID to be API Login ID, and refreshed Transaction Key and MD5 Hash to ensure they match. But I keep getting the error, despite the fact that my Authorize.Net account shows that it knows that it's in Test Mode and not Live Mode.

While I'll go to Authorize.Net to see what they know, I have a question on Open Cart. In the shopping cart I used before with Authorize.Net, the credit card info would be collected first, then sent. Open Cart doesn't collect the info first. Does this change how I have to approach Authorize.Net? Could this be part of the error I'm getting, to somehow indicate that Authorize.Net should collect the info? Maybe things are entering Authorize.Net in an unexpected format?

What do you mean by "collected" ? You mean you want to save the actual card number locally? or you mean it is authorized first and then captured later?

Previously, the user entered their credit card number on our shopping cart site before the transaction went to Authorize.net.

I do not necessarily want to have them enter the data on our site. Personally I would like to be as far away from it as possible. But I'm just wondering if that is a difference in the two shopping cart sites and the two results.

I have more info from Authorize.Net regarding why this is failing. Their opinion is that the Open Cart script is sending to the wrong URL.

Apparently what is commonly used is either https://secure.authorize.net/gateway/transact.dll or https://secure2.authorize.net/gateway/transact.dll , for live transactions.

Their advice was to check the script to verify if it's sending to the correct URL. (Their previous advice was to run as a live transaction, but I turned test mode off on both sides, and still get the same error).

How can I check the script in Open Cart?

Also, there is a tool to see if you are sending the right info. Their help says:

The Data Validation Tool helps developers check the syntax of name/value pairs. Changing the
Transaction POST URL in your script from https://test.authorize.net/gateway/transact.dll to
http://developer.authorize.net/bin/developer/paramdump will display the transaction results.
You can then verify that all field names and values in your transaction request are correct.

Again, how can I access the script in order to do this? I don't know what I'm looking for.

This is very frustrating. Open Cart should just work without me having to change scripts. I've configured (and confirmed the veracity on the Authorize.Net side) my Open Cart settings for Authorize.Net SIM as follows:

* Merchant ID field = my API Login ID.
* Transaction key = my Transaction key.
* MD5 Hash = my MD5 Hash.

I don't know what else I can do.

If you are using the SIM module that comes with OpenCart I believe that is unfinished.
I offer the only known working SIM module here:
http://www.opencart.com/index.php?route ... n_id=22006
and it does have the correct urls as well as a way to switch to the test or sandbox urls