diff --git a/ajax/question_add.php b/ajax/question_add.php
index 3055a6397..6f6c8ade3 100644
--- a/ajax/question_add.php
+++ b/ajax/question_add.php
@@ -41,9 +41,7 @@
 }
 
 if (!$question->add($_REQUEST)) {
-    http_response_code(500);
-    echo array_shift($_SESSION['MESSAGE_AFTER_REDIRECT'][ERROR]);
-    unset($_SESSION['MESSAGE_AFTER_REDIRECT'][ERROR]);
+    http_response_code(400);
     exit;
 }
 $json = [
diff --git a/js/scripts.js.php b/js/scripts.js.php
index e9c805e68..e291948ce 100644
--- a/js/scripts.js.php
+++ b/js/scripts.js.php
@@ -817,13 +817,9 @@ function buildTiles(list) {
          data: form.serializeArray(),
          dataType: 'json'
       }).fail(function(data) {
-         // Closing and opening the modal workarounds
-         // the whole modal being disabled when alert is shown
-         // modalWindow.dialog('close');
-         // alert(data.responseText);
-         // modalWindow.dialog('open');
-         $('#plugin_formcreator_error').text(data.responseText);
-         $('#plugin_formcreator_error').show();
+         // fix for GLPI <= 9.5.2
+         $('[id^="message_after_redirect_"]').remove();
+         displayAjaxMessageAfterRedirect();
       }).done(function(data) {
          var sectionId = form.find('select[name="plugin_formcreator_sections_id"]').val();
          var container = $('[data-itemtype="PluginFormcreatorSection"][data-id="' + sectionId + '"] .grid-stack');