diff -u b/core/modules/book/book.module b/core/modules/book/book.module
--- b/core/modules/book/book.module
+++ b/core/modules/book/book.module
@@ -126,8 +126,8 @@
   if (isset($node->book['depth'])) {
     if ($view_mode == 'full' && node_is_page($node)) {
       $child_type = config('book.settings')->get('child_type');
-      $account = Drupal::request()->attributes->get('_account');
-      if (($account->hasPermission('add content to books') || $account->hasPermission('administer book outlines')) && node_access('create', $child_type) && $node->status == 1 && $node->book['depth'] < MENU_MAX_DEPTH) {
+      $user = Drupal::request()->attributes->get('_account');
+      if (($user->hasPermission('add content to books') || $user->hasPermission('administer book outlines')) && node_access('create', $child_type) && $node->status == 1 && $node->book['depth'] < MENU_MAX_DEPTH) {
         $links['book_add_child'] = array(
           'title' => t('Add child page'),
           'href' => 'node/add/' . $child_type,
@@ -135,7 +135,7 @@
         );
       }
 
-      if ($account->hasPermission('access printer-friendly version')) {
+      if ($user->hasPermission('access printer-friendly version')) {
         $links['book_printer'] = array(
           'title' => t('Printer-friendly version'),
           'href' => 'book/export/html/' . $node->id(),
@@ -225,7 +225,9 @@
  *   The node whose export page is to be viewed.
  */
 function book_export_access(EntityInterface $node) {
-  return Drupal::request()->attributes->get('_account')->hasPermission('access printer-friendly version') && node_access('view', $node);
+  $user = Drupal::request()->attributes->get('_account');
+  $user = (empty($user)) ? drupal_anonymous_user() : $user;
+  return $user->hasPermission('access printer-friendly version') && node_access('view', $node);
 }
 
 /**
@@ -306,11 +308,11 @@
  */
 function book_form_node_form_alter(&$form, &$form_state, $form_id) {
   $node = $form_state['controller']->getEntity();
-  $account = Drupal::request()->attributes->get('_account');
-  $access = $account->hasPermission('administer book outlines');
+  // Get current user object.
+  $user = Drupal::request()->attributes->get('_account');
+  $access = $user->hasPermission('administer book outlines');
   if (!$access) {
-
-    if ($account->hasPermission('add content to books') && ((!empty($node->book['mlid']) && !$node->isNew()) || book_type_is_allowed($node->type))) {
+    if ($user->hasPermission('add content to books') && ((!empty($node->book['mlid']) && !$node->isNew()) || book_type_is_allowed($node->type))) {
       // Already in the book hierarchy, or this node type is allowed.
       $access = TRUE;
     }
@@ -882,9 +884,10 @@
  * Implements hook_node_prepare_form().
  */
 function book_node_prepare_form(NodeInterface $node, $form_display, $operation, array &$form_state) {
+  // Get current user object.
+  $user = Drupal::request()->attributes->get('_account');
   // Prepare defaults for the add/edit form.
-  $account = Drupal::request()->attributes->get('_account');
-  if (empty($node->book) && ($account->hasPermission('add content to books') || $account->hasPermission('administer book outlines'))) {
+  if (empty($node->book) && ($user->hasPermission('add content to books') || $user->hasPermission('administer book outlines'))) {
     $node->book = array();
 
     $query = \Drupal::request()->query;