diff --git a/core/includes/ajax.inc b/core/includes/ajax.inc
index c5bdb1a..3042bea 100644
--- a/core/includes/ajax.inc
+++ b/core/includes/ajax.inc
@@ -369,7 +369,7 @@ function ajax_prepare_response($page_callback_result) {
         break;
 
       case MENU_SITE_OFFLINE:
-        $commands[] = ajax_command_alert(Xss::filterAdmin(t(\Drupal::config('system.maintenance')->get('message'), array('@site' => Drupal::config('system.site')->get('name')))));
+        $commands[] = ajax_command_alert(Xss::filterAdmin(t(\Drupal::config('system.maintenance')->get('message'), array('@site' => \Drupal::config('system.site')->get('name')))));
         break;
     }
   }
diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index 4eae1e3..399c9fb 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -1692,8 +1692,7 @@ function drupal_get_title() {
  *   Optional flag - normally should be left as Title::CHECK_PLAIN. Only set to
  *   PASS_THROUGH if you have already removed any possibly dangerous code
  *   from $title using a function like
- *   \Drupal\Component\Utility\String::checkPlain() or
- *   \Drupal\Component\Utility\Xss::filterAdmin(). With this
+ *   \Drupal\Component\Utility\String::checkPlain() or filter_xss(). With this
  *   flag the string will be passed through unchanged.
  *
  * @return
diff --git a/core/includes/errors.inc b/core/includes/errors.inc
index 08a523c..0c19c29 100644
--- a/core/includes/errors.inc
+++ b/core/includes/errors.inc
@@ -376,7 +376,7 @@ function format_backtrace(array $backtrace) {
     }
     foreach ($trace['args'] as $arg) {
       if (is_scalar($arg)) {
-        $call['args'][] = is_string($arg) ? '\'' . Xss::filterAdmin($arg) . '\'' : $arg;
+        $call['args'][] = is_string($arg) ? '\'' . filter_xss($arg) . '\'' : $arg;
       }
       else {
         $call['args'][] = ucfirst(gettype($arg));
diff --git a/core/modules/block/custom_block/custom_block.pages.inc b/core/modules/block/custom_block/custom_block.pages.inc
index b312b82..f24e16b 100644
--- a/core/modules/block/custom_block/custom_block.pages.inc
+++ b/core/modules/block/custom_block/custom_block.pages.inc
@@ -26,7 +26,7 @@ function template_preprocess_custom_block_add_list(&$variables) {
   $query = \Drupal::request()->query->all();
   foreach ($variables['content'] as $type) {
     $variables['types'][$type->id()] = array(
-      'link' => \Drupal::l($type->label(), 'custom_block_add_form', array('custom_block_type' => $type->id()), array('query' => $query)),
+      'link' => \Drupal::l($type->label(), 'custom_block.add_form', array('custom_block_type' => $type->id()), array('query' => $query)),
       'description' => Xss::filterAdmin($type->description),
       'title' => $type->label(),
       'localized_options' => array(