Products' URL: Template File Changes for Zen Cart 1.5.3 and later

Starting with Zen Cart v1.5.3, the built-in handling that displays a product’s URL was changed. If you are upgrading your store from a previous version of Zen Cart and you want your products’ URLs to continue to properly display, make sure to merge the following changes into your template’s tpl_*_display.php files. In each file, look for:

<!--bof Product URL -->
<?php
  if (zen_not_null($products_url)) {
    if ($flag_show_product_info_url == 1) {
?>
    <p id="productInfoLink" class="productGeneral centeredContent"><?php echo sprintf(TEXT_MORE_INFORMATION, zen_href_link(FILENAME_REDIRECT, <strong>'action=url&goto=' . urlencode($products_url)</strong>, 'NONSSL', true, false)); ?></p>
<?php
    } // $flag_show_product_info_url
  }
?>
<!--eof Product URL -->

and make sure that the highlighted section is changed to:

<!--bof Product URL -->
<?php
  if (zen_not_null($products_url)) {
    if ($flag_show_product_info_url == 1) {
?>
    <p id="productInfoLink" class="productGeneral centeredContent"><?php echo sprintf(TEXT_MORE_INFORMATION, zen_href_link(FILENAME_REDIRECT, 'action=product&products_id=' . zen_output_string_protected($_GET['products_id']), 'NONSSL', true, false)); ?><p>
<?php 
    } // $flag_show_product_info_url 
  } ?>
<!--eof Product URL -->

Making that change will allow your Zen Cart v1.5.3+ store to continue to properly display your products’ URLs.