Internet Explorer error

-- HikaShop version -- : 2.6.0
-- Joomla version -- : 3.4.5
-- PHP version -- : 5.4.28
-- Browser(s) name and version -- : Internet Explorer
-- Error-message(debug-mod must be tuned on) -- : What Payeezy sents back as redirect URL when using Chrome:

checkout.globalgatewaye4.firstdata.com/c...&purch=139539257&t=1

What Payeezy sents back as redirect URL when using IE:

checkout.globalgatewaye4.firstdata.com/c...&purch=139532853&t=2

From 1st Data Payeezy:
I was able to duplicate the issue in IE. I switched out the notification email to my email address and attempted to process a test transaction. I received the email confirming my test order. However, I did not receive a notification email indicating the error in accessing the payment page. The fact that I did not receive the notification email and that only IE seems to be affected leads me to believe that the issue is with your shopping cart. There is something in their setup that is keeping the page from loading in IE.
1st Data said:
Thank you for contacting the help desk. I was able to duplicate the issue in IE. I switched out the notification email to my email address and attempted to process a test transaction. I received the email confirming my test order. However, I did not receive a notification email indicating the error in accessing the payment page. The fact that I did not receive the notification email and that only IE seems to be affected leads me to believe that the issue is with your shopping cart. There is something in their setup that is keeping the page from loading in IE. Please contact them for further troubleshooting.

What we did:
I spent hours debugging this problem. I compared the requests of Google Chrome and Internet Explorer 10 one by one and line by line and they are identical which leads me to believe that this is a payeezy problem. The fact that payeezy doesn't produce nor sent a meaningful error message makes this impossible to fix.

As you can see, in the IE case the variable "merchant" and it's value are missing despite having gotten the exact same request parameters from both browsers.

1st Data says:
they are saying that the shopping cart has some programming or settings for how it directs the user to the payment page and that it is correct for Chrome and Firefox; but for IE, something is missing.
They say that our shopping cart sends the request to firstdata for the payment page, so the fact that the merchant is missing is some kind of setting for IE browser in the shopping cart.

So you're saying that the problem is NOT in Hikashop and no way it can be?
The problem is with the gateway service that's being used? In this case its 1st Data/Payeezy.
And it's not the IE browser at all?
A server setting at the hosting company where our site is hosted?

nicolas wrote: Hi,

As you said, the authorize.net payment plugin sends the exact same thing regardless of the browser used.
So I don't see how it could come from HikaShop. And HikaShop has no setting for IE or another browser and not one PHP line of code specific to a particular browser.
Potentially if the server handles the communication differently ? Or another plugin of the website which would interfere (although I don't see why that would be the case) ? Or maybe your Joomla template (try with the protostar template once to make sure that it doesn't come from it) ?