File Upload required addon problem

[chriscctx]

I have tried on several occasions to install the "File upload required" add-on to three different themes. I attempted this on three different ones thinking it was a problem with the themes but after three I am doing something wrong. After hitting "add to cart" I get a blank screen. This is after over-riding the specific file requested in the "file upload required" instructions.

I get this error in the log - PHP Fatal error: Call to undefined function ACVValidatePX() in /home3/userhere/public_html/abcdefghijklmn.com/shopnow/includes/classes/shopping_cart.php on line 1711

If I go back and install the shopping_cart.php from the original 1.5.1 zen cart it works again. So I am thinking there is an issue with "file upload required".

Any help would be appreciated.

[twitchtoo]

Are you overwriting the files or are you carefully merging them with something like winmerge ?