diff --git a/controller/WebController.php b/controller/WebController.php
index 4d8c8740c..ce3078000 100644
--- a/controller/WebController.php
+++ b/controller/WebController.php
@@ -550,6 +550,7 @@ public function invokeGenericErrorPage($request, $message = null)
             array(
                 'languages' => $this->languages,
                 'request' => $request,
+                'vocab' => $request->getVocab(),
                 'message' => $message,
                 'requested_page' => filter_input(INPUT_SERVER, 'REQUEST_URI', FILTER_SANITIZE_STRING),
             ));
diff --git a/resource/css/styles.css b/resource/css/styles.css
index 0f83fb22b..c6489e3ed 100644
--- a/resource/css/styles.css
+++ b/resource/css/styles.css
@@ -1074,7 +1074,7 @@ li.sub-group {
   right: 0;
 }
 
-.page-alert > h3 {
+.frontpage-alert > h3, .page-alert > h3 {
   margin: 10px 0px;
 }
 
diff --git a/resource/js/docready.js b/resource/js/docready.js
index f69728922..0a7884e47 100644
--- a/resource/js/docready.js
+++ b/resource/js/docready.js
@@ -1042,9 +1042,9 @@ $(function() { // DOCUMENT READY
   }
 
   /* makes an AJAX query for the alphabetical index contents when landing on
-   * the vocabulary home page.
+   * the vocabulary home page or on the vocabulary concept error page.
    */
-  if ($('#alpha').hasClass('active') && $('#vocab-info').length === 1 && $('.alphabetical-search-results').length === 0) {
+  if ($('#alpha').hasClass('active') && $('#vocab-info,.page-alert').length == 1 && $('.alphabetical-search-results').length == 0) {
     // taking into account the possibility that the lang parameter has been changed by the WebController.
     var urlLangCorrected = vocab + '/' + lang + '/index?limit=250&offset=0&clang=' + clang;
     $('.sidebar-grey').empty().append('<div class="loading-spinner"><span class="spinner-text">'+ loading_text + '</span><span class="spinner" /></div>');
diff --git a/view/error-page.twig b/view/error-page.twig
index f12efd68b..d1bf7d987 100644
--- a/view/error-page.twig
+++ b/view/error-page.twig
@@ -1,11 +1,18 @@
 {% extends "light.twig" %}
 {% block title %}: Error page{% endblock %}
 {% block error %}
+{% spaceless %}
+{% set pageError = request.vocabid != '' and request.page == 'page' %}
+{% if pageError %}
 <div id="maincontent">
   <div class="content">
+{% endif %}
     <div class="alert {% if request.vocabid != '' or request.page == 'feedback' or request.page == 'about' %}page-alert{% else %}frontpage-alert{% endif %}">
       <h3>{% if not message %}{% trans %}404 Error: The page {{ requested_page }} cannot be found.{% endtrans %}{% else %}{{ message }}{% endif %}</h3>
     </div>
+{% if pageError %}
   </div>
 </div>
+{% endif %}
+{% endspaceless %}
 {% endblock %}