Try a fix for #6024

htdocs/fourn/facture/card.php

@@ -1765,7 +1765,7 @@ else
                     print '<tr '.$bc[$var].'><td>';
 					$paymentstatic->id=$objp->rowid;
 					$paymentstatic->datepaye=$db->jdate($objp->dp);
-					$paymentstatic->ref=$objp->ref;
+					$paymentstatic->ref=($objp->ref ? $objp->ref : $objp->rowid);
 					$paymentstatic->num_paiement=$objp->num_paiement;
 					$paymentstatic->payment_code=$objp->payment_code;
 					print $paymentstatic->getNomUrl(1);