diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 4f5c752..5ece44d 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -1748,7 +1748,7 @@ function drupal_common_theme() {
       'variables' => array('items' => NULL, 'active' => NULL,  'variant' => NULL),
     ),
     'authorize_report' => array(
-      'variables' => ['messages' => [], 'report' => [], 'attributes' => []],
+      'variables' => ['messages' => [], 'attributes' => []],
       'includes' => ['core/includes/theme.maintenance.inc'],
       'template' => 'authorize-report',
     ),
diff --git a/core/includes/theme.maintenance.inc b/core/includes/theme.maintenance.inc
index 68aff41..b60df6b 100644
--- a/core/includes/theme.maintenance.inc
+++ b/core/includes/theme.maintenance.inc
@@ -111,6 +111,7 @@ function _drupal_maintenance_theme() {
  *   - messages: An array of result messages.
  */
 function template_preprocess_authorize_report(&$variables) {
+  $variables['report'] = [];
   $messages = $variables['messages'];
   if (!empty($messages)) {
     foreach ($messages as $heading => $logs) {
diff --git a/core/lib/Drupal/Core/Theme/Registry.php b/core/lib/Drupal/Core/Theme/Registry.php
index bb89707..d24802d 100644
--- a/core/lib/Drupal/Core/Theme/Registry.php
+++ b/core/lib/Drupal/Core/Theme/Registry.php
@@ -442,6 +442,13 @@ protected function processExtension(array &$cache, $name, $type, $theme, $path)
           $result[$hook]['includes'] = $cache[$hook]['includes'];
         }
 
+        // Load the includes, as they may contain preprocess functions.
+        if (isset($info['includes'])) {
+          foreach ($info['includes'] as $include_file) {
+            include_once $this->root . '/' . $include_file;
+          }
+        }
+
         // If the theme implementation defines a file, then also use the path
         // that it defined. Otherwise use the default path. This allows
         // system.module to declare theme functions on behalf of core .include
diff --git a/core/lib/Drupal/Core/Updater/Module.php b/core/lib/Drupal/Core/Updater/Module.php
index 5318f0a..2385fd3 100644
--- a/core/lib/Drupal/Core/Updater/Module.php
+++ b/core/lib/Drupal/Core/Updater/Module.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\Core\Updater;
 
-use Drupal\Core\Routing\RequestContext;
 use Drupal\Core\Url;
 
 /**