core/modules/big_pipe/src/Render/BigPipe.php                     | 4 +++-
 core/modules/big_pipe/src/Render/Placeholder/BigPipeStrategy.php | 3 +--
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/core/modules/big_pipe/src/Render/BigPipe.php b/core/modules/big_pipe/src/Render/BigPipe.php
index 19112f0..2fbc323 100644
--- a/core/modules/big_pipe/src/Render/BigPipe.php
+++ b/core/modules/big_pipe/src/Render/BigPipe.php
@@ -348,7 +348,9 @@ protected function sendPlaceholders(array $placeholders, array $placeholder_orde
       // Another placeholder was rendered and sent, track the set of asset
       // libraries sent so far. Any new settings are already sent; we don't need
       // to track those.
-      $cumulative_assets->setAlreadyLoadedLibraries(explode(',', $ajax_response->getAttachments()['drupalSettings']['ajaxPageState']['libraries']));
+      if (isset($ajax_response->getAttachments()['drupalSettings']['ajaxPageState']['libraries'])) {
+        $cumulative_assets->setAlreadyLoadedLibraries(explode(',', $ajax_response->getAttachments()['drupalSettings']['ajaxPageState']['libraries']));
+      }
     }
 
     // Send the stop signal.
diff --git a/core/modules/big_pipe/src/Render/Placeholder/BigPipeStrategy.php b/core/modules/big_pipe/src/Render/Placeholder/BigPipeStrategy.php
index 58eb50b..b672c6c 100644
--- a/core/modules/big_pipe/src/Render/Placeholder/BigPipeStrategy.php
+++ b/core/modules/big_pipe/src/Render/Placeholder/BigPipeStrategy.php
@@ -72,8 +72,7 @@ public function __construct(AccountInterface $current_user) {
    * {@inheritdoc}
    */
   public function processPlaceholders(array $placeholders) {
-    // @todo Move to a ResponsePolicy instead.
-    // @todo Add user.roles:authenticated cache context.
+    // @todo Remove in https://www.drupal.org/node/2603046.
     if (!$this->currentUser->isAuthenticated()) {
       return [];
     }