diff --git a/inc/ticket.class.php b/inc/ticket.class.php
index 5e58bad..357b7e9 100644
--- a/inc/ticket.class.php
+++ b/inc/ticket.class.php
@@ -1264,7 +1264,7 @@ public function showForm($ID, $options = [])
         $condition = [
             'is_assign' => 1,
         ];
-        if ($config->fields['use_filter_assign_group'] && !$user_config->fields['bypass_filter_assign_group']) {
+        if ($config->fields['use_filter_assign_group'] && isset($user_config->fields['bypass_filter_assign_group']) && !$user_config->fields['bypass_filter_assign_group']) {
             $condition['id'] = $groups_id_filtered;
         }
         TemplateRenderer::getInstance()->display('@escalade/escalade_form.html.twig', [