Unknown price field used: [] error

I am doing a customization of signup.php to allow a user to register for a free product. The code works on localhost but when I try it out in my test environment am getting the following error: Unknown price field used: []

It actually creates a new user but fails to send out the opt in email.

Thanks in advance!

Bob

What edits did you do to the product area?

David

David, thanks for your quick reply. I did in fact change the product (and the paysystem) section as follows:

<input type="hidden" id="product{$p.product_id}" name="product_id" value="3" />
{foreach from=$paysystems item=p}
<input type="hidden" id="paysys_id{$p.paysys_id}" name="paysys_id" value="{$p.paysys_id|escape}" />
{/foreach}

Notice the value="3" which is a hardcoded product id. Well on my test system the value is "5". I changed this and everything started working!

I will fix the above code to use a non-hardcoding technique. It's too dangerous to leave it this way.