diff --git a/core/includes/errors.inc b/core/includes/errors.inc
old mode 100644
new mode 100755
index 40e2903..33298ac
--- a/core/includes/errors.inc
+++ b/core/includes/errors.inc
@@ -265,6 +265,12 @@ function _drupal_log_error($error, $fatal = FALSE) {
         exit;
       }
 
+      $html = Error::renderFatalError(['title' => 'Service unavailable', 'message' => $message]);
+      if (!empty($html)) {
+        $message = $html;
+        $response->headers->set('Content-Type', 'text/html');
+      }
+
       $response->setContent($message);
       $response->setStatusCode(500, '500 Service unavailable (with message)');
 
diff --git a/core/lib/Drupal/Core/EventSubscriber/FinalExceptionSubscriber.php b/core/lib/Drupal/Core/EventSubscriber/FinalExceptionSubscriber.php
old mode 100644
new mode 100755
index 4317ff0..313d573
--- a/core/lib/Drupal/Core/EventSubscriber/FinalExceptionSubscriber.php
+++ b/core/lib/Drupal/Core/EventSubscriber/FinalExceptionSubscriber.php
@@ -125,7 +125,15 @@ public function onException(GetResponseForExceptionEvent $event) {
 
     $content = $this->t('The website encountered an unexpected error. Please try again later.');
     $content .= $message ? '</br></br>' . $message : '';
-    $response = new Response($content, 500, ['Content-Type' => 'text/plain']);
+    $type = 'text/plain';
+
+    $html = Error::renderFatalError(['title' => $this->t('Service unavailable'), 'message' => $content]);
+    if (!empty($html)) {
+      $content = $html;
+      $type = 'text/html';
+    }
+
+    $response = new Response($content, 500, ['Content-Type' => $type]);
 
     if ($exception instanceof HttpExceptionInterface) {
       $response->setStatusCode($exception->getStatusCode());
diff --git a/core/lib/Drupal/Core/Utility/Error.php b/core/lib/Drupal/Core/Utility/Error.php
old mode 100644
new mode 100755
index eb452c2..8dd8de5
--- a/core/lib/Drupal/Core/Utility/Error.php
+++ b/core/lib/Drupal/Core/Utility/Error.php
@@ -5,6 +5,8 @@
 use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Component\Utility\Xss;
 use Drupal\Core\Database\DatabaseExceptionWrapper;
+use Twig_Environment;
+use Twig_Loader_Array;
 
 /**
  * Drupal error utility class.
@@ -101,6 +103,45 @@ public static function renderExceptionSafe($exception) {
   }
 
   /**
+   * Renders fatal error page from twig template using Symfony twig engine.
+   *
+   * @param array $context
+   *   Variables to be passed to twig template.
+   *
+   * @return string
+   *   An html code with rendered fatal error page.
+   */
+  public static function renderFatalError(array $context) {
+    $content = '';
+
+    // Try to get the current theme. If this fails,
+    // for example if the database connection is not there, use bartik.
+    try {
+      $theme = \Drupal::service('theme.manager')->getActiveTheme()->getName();
+      $path = DRUPAL_ROOT . '/' . drupal_get_path('theme', $theme) . '/templates/fatal-error-page.html.twig';
+    }
+    catch (\Exception $e) {
+      $path = DRUPAL_ROOT . '/core/themes/bartik/templates/fatal-error-page.html.twig';
+    }
+
+    if (file_exists($path)) {
+      // Directly use Symfony twig engine without Drupal wrapper to minimize
+      // possibility of nested exception.
+      $environment = new Twig_Environment();
+      $template = file_get_contents($path);
+      $loader = new Twig_Loader_Array(['fatal_error' => $template]);
+      $environment->setLoader($loader);
+
+      $context = array_map(function ($v) {
+        return trim(strip_tags($v));
+      }, $context);
+      $content = $environment->render('fatal_error', $context);
+    }
+
+    return $content;
+  }
+
+  /**
    * Gets the last caller from a backtrace.
    *
    * @param array $backtrace
diff --git a/core/themes/bartik/templates/fatal-error-page.html.twig b/core/themes/bartik/templates/fatal-error-page.html.twig
new file mode 100755
index 0000000..50a30c8
--- /dev/null
+++ b/core/themes/bartik/templates/fatal-error-page.html.twig
@@ -0,0 +1,41 @@
+{#
+/**
+ * @file
+ * Bartik's theme implementation to display a fatal error page.
+ *
+ */
+ #}
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <title>
+    {% if title %}
+      {{ title }}
+    {% else %}
+      Service unavailable
+    {% endif %}
+  </title>
+  <style media="all">
+    @import url("/core/themes/bartik/css/maintenance-page.css");
+  </style>
+</head>
+<body class="maintenance-page layout-no-sidebars path-frontpage">
+  <div id="page-wrapper">
+    <div id="page">
+      <div id="main-wrapper">
+        <div id="main" class="clearfix">
+          <main id="content" class="column" role="main">
+            <section class="section">
+              <a id="main-content"></a>
+              {% if title %}
+                <h1 class="title" id="page-title">{{ title }}</h1>
+              {% endif %}
+              {{ message }}
+            </section>
+          </main>
+        </div>
+      </div>
+    </div>
+  </div>
+</body>
+</html>