erreur panier

-- url of the page with the problem -- : gec.gestion-elevage-canin.fr/index.php/l.../product/gc-windows/
-- HikaShop version -- : 4.7.3
-- Joomla version -- : Joomla! 4.3.2 Stable [ Bora ] 30-May-2023 16:00 GMT
-- PHP version -- : 8.1.20
-- Browser(s) name and version -- : Firefox 114.0.1
-- Error-message(debug-mod must be tuned on) -- : Deprecated: htmlspecialchars(): Passing null to parameter #1 ($string) of type string is deprecated in /homepages/43/d146339572/htdocs/gec_2022/templates/rt_horizon/html/layouts/chromes/gantry.php on line 31

Bonjour, le panier affiche ce message d'erreur.
Merci pour une solution

Deprecated: htmlspecialchars(): Passing null to parameter #1 ($string) of type string is deprecated in /homepages/43/d146339572/htdocs/gec_2022/templates/rt_horizon/html/layouts/chromes/gantry.php on line 31

OK, thanks a lot.
Merci beaucoup.