An unknown response null::text/html ::FORBIDDEN was received

I am having the same problem, when i add to cart a product, it prompts me that error, I am using: v1.5.4, can you help me how to fix this problem?

@roxannepercy, have you made the updates that mc12345678 identified in post #2 of this thread?

lat9:

@roxannepercy, have you made the updates that mc12345678 identified in post #2 of this thread?

Yes, I have. All.

Is the error message EXACTLY the same? There are about 5 different versions of that error message, and each means a different thing.

Is yours "response null :text/html" .... "unexpected token m ..."?
or "response null:null:" ..... "undefined var"....?
etc?

That is exactly what happen when i add an item to cart, i am using v 1.5.4, as per the directions above, i cant seem to understand it. Can you help me please

roxannepercy:

I am having the same problem, when i add to cart a product, it prompts me that error, I am using: v1.5.4, can you help me how to fix this problem?

roxannepercy:

That is exactly what happen when i add an item to cart, i am using v 1.5.4, as per the directions above, i cant seem to understand it. Can you help me please
So, it's not exactly the same reason. Your message is different ... similar, but the subtle difference is major.

Yours shows the word "Forbidden" as the reason.
... which suggests you're getting a "403 Forbidden" response to an ajax call.
... which is usually caused by the incoming request being disallowed for security reasons, or it's trying to make an ajax call to a file/URL that's inside a restricted location, or your server's permissions on the ajax.php file are set too low (or in some cases it could be that the file is missing, although that'd probably give a "404 Not Found" response instead).

Given that you're using v1.5.4, I suggest you follow the installation instructions for the template addon that you've installed to ensure that you've placed all its necessary components on your server correctly.

Is there no other way, i cant really identify what cause the problem..

Judging from the response obtained from the server when triggering that error, you're missing the /ajax.php file that came with Zen Cart.
Or maybe you or your hosting company deleted it.

You can grab the latest version of that file **for v1.5.4 **from the link on this announcement: https://www.zen-cart.com/showthread.php?218914-Security-Patches-for-v1-5-4-November-2015

Or if you're actually using the newer v1.5.5 then the latest for v1.5.5 is available at https://github.com/zencart/zencart/raw/v155/ajax.php

It goes into the same directory where your ipn_main_handler.php file is located.