// check post & get value
    foreach ($_POST as $k => $v) {
        if (!in_array($k, array('FS', 'IP', 'CODE', 'TIME'))) {
            if (is_array($v)) {
                foreach ($v as $sub_k => $sub_v) {
                    // Fixed $$k to $k and added null check for PHP 8
                    $_POST[$k][$sub_k] = htmlspecialchars($sub_v ?? '', ENT_QUOTES, 'UTF-8', false);
                }
            } else {
                $_POST[$k] = htmlspecialchars($v ?? '', ENT_QUOTES, 'UTF-8', false);
            }
        }
    }

    foreach ($_GET as $k => $v) {
        if (!in_array($k, array('FS', 'IP', 'CODE', 'TIME'))) {
            if (is_array($v)) {
                foreach ($v as $sub_k => $sub_v) {
                    // Fixed $$k to $k and added null check for PHP 8
                    $_GET[$k][$sub_k] = htmlspecialchars($sub_v ?? '', ENT_QUOTES, 'UTF-8', false);
                }
            } else {
                $_GET[$k] = htmlspecialchars($v ?? '', ENT_QUOTES, 'UTF-8', false);
            }
        }
    }<br />
<b>Fatal error</b>:  Uncaught  --&gt; Smarty: Unable to load template file 'index.tpl' &lt;-- 
  thrown in <b>/home/jackbrea/public_html/include/smarty/sysplugins/smarty_internal_templatebase.php</b> on line <b>129</b><br />