diff --git a/block_aria_landmark_roles.module b/block_aria_landmark_roles.module
--- a/block_aria_landmark_roles.module
+++ b/block_aria_landmark_roles.module	(date 1644252260842)
@@ -48,6 +48,10 @@
   if (!empty($variables['elements']['#id'])) {
     $block = Block::load($variables['elements']['#id']);

+    if (is_null($block)) {
+      return FALSE;
+    }
+
     if ($role = $block->getThirdPartySetting('block_aria_landmark_roles', 'role')) {
       $variables['attributes']['role'] = $role;
     }