Issue #3276411: SocialCommentBreadcrumbBuilder causes an error loading entities

modules/social_features/social_comment/src/SocialCommentBreadcrumbBuilder.php

@@ -57,12 +57,15 @@ class SocialCommentBreadcrumbBuilder implements BreadcrumbBuilderInterface {
     $breadcrumb->addCacheContexts(['route']);
     $breadcrumb->addLink(Link::createFromRoute($this->t('Home'), '<front>'));
     $breadcrumb->addLink(Link::createFromRoute($this->t('Home'), '<front>'));
+    $comment = FALSE;
 
     switch ($route_match->getRouteName()) {
       case 'comment.reply':
         $page_title = $this->t('Reply to Comment');
         $pid = $route_match->getParameter('pid');
-        $comment = $this->storage->load($pid);
+        if ($pid) {
+            $comment = $this->storage->load($pid);
+        }
         break;
 
       case 'entity.comment.edit_form':