Add to Cart Not Working - Which Files to Look For?

Hi all,

First off, my site url is http://bit.ly/osvjH2
We had some modules installed and customizations recently, so I think there might have been tiny little mistakes with some files.

The add to cart button does not work (returns blank page), but I have no idea which files to look for to fix it.

Is there a way to
- find out what the problem is (a blank space? a blank line? more serious problems?)
- and in which file to fix it


Thank you so much for your help!

Also, for some reason the cache folder returns 'data error.' Are these problems interrelated?

Nothing in my error log so nowhere I can look in help articles. Anyone?

I think the file you need to look at is:

includes/languages/english/your_template/shopping_cart.php

Try uploading a fresh copy and see what happens. Note: If you aren't using overrides, you can drop "your_template" from the path.

Thanks for your tip Resco. But uploading a fresh copy didn't do the magic :(

Any other suggestions?

Okay, try:

includes/classes/shopping_cart.php

Also no change. :no:

Looks like you got this fixed

Ok here's the summary of what I did:

1. Go through every single file to check if any files have a line or space before the first letter of the file.
Turns out a LOT of them had it so I'm not going to list everything here.
(Also, anything with shopping_cart in its name DIDN'T have any space or line before it, so I guess files are interrelated and you just have to check everything.)

With this first step, no blank page occurred but I got a "your cart is empty" message instead.

So I did what this guy said in this thread: http://www.zen-cart.com/forum/showthread.php?t=177200

2. "Admin->Configuration->Sessions->Add period prefix to cookie domain to False resolved the problem"

It did!!!!

Thanks everyone who commented & helped :)

Thanks for the solution, this worked for me too. Strange that the shopping cart worked fine before - must have been some change in server environment!