I work on a site developed a few years ago by someone else. An intranet had been developed on this site. A page of this intranet had to list elements does not work.

Here are the first lines, I think the problem comes from there :

<?php
    require_once('init.php');
    require('header.php');
    $product = get_term_by('slug', $_GET['title'], 'product');
?>

"$_GET['title']" steal empty, and I have never seen the use of $_GET in Wordpress...

On this page, the loop is working well, but I have to use term object to display term title for example.