diff --git a/src/Controller/User/ThemeSettingsController.php b/src/Controller/User/ThemeSettingsController.php
index 5dbc73566..e94efc5e3 100644
--- a/src/Controller/User/ThemeSettingsController.php
+++ b/src/Controller/User/ThemeSettingsController.php
@@ -168,13 +168,21 @@ public function __invoke(string $key, string $value, Request $request): Response
         );
     }
 
-    public static function getShowUserFullName(Request $request): bool
+    public static function getShowUserFullName(?Request $request): bool
     {
+        if (null === $request) {
+            return false;
+        }
+
         return self::TRUE === $request->cookies->get(self::MBIN_SHOW_USER_DOMAIN, 'false');
     }
 
-    public static function getShowMagazineFullName(Request $request): bool
+    public static function getShowMagazineFullName(?Request $request): bool
     {
+        if (null === $request) {
+            return false;
+        }
+
         return self::TRUE === $request->cookies->get(self::MBIN_SHOW_MAGAZINE_DOMAIN, 'false');
     }
 }
diff --git a/src/Markdown/CommonMark/ExternalLinkRenderer.php b/src/Markdown/CommonMark/ExternalLinkRenderer.php
index d1b4306fc..417a4726f 100644
--- a/src/Markdown/CommonMark/ExternalLinkRenderer.php
+++ b/src/Markdown/CommonMark/ExternalLinkRenderer.php
@@ -91,17 +91,20 @@ public function render(Node $node, ChildNodeRendererInterface $childRenderer): H
             ]);
         }
 
-        $apActivity = $this->activityRepository->findByObjectId($node->getUrl());
-        if (!$isApRequest && null !== $apActivity && Message::class !== $apActivity['type']) {
-            $this->logger->debug('Found activity with url {u}: {t} - {id}', [
-                'u' => $node->getUrl(),
-                't' => $apActivity['type'],
-                'id' => $apActivity['id'],
-            ]);
-            /** @var Entry|EntryComment|Post|PostComment $entity */
-            $entity = $this->entityManager->getRepository($apActivity['type'])->find($apActivity['id']);
-
-            return new HtmlElement('div', contents: $this->renderInlineEntity($entity));
+        $url = $node->getUrl();
+        if (filter_var($url, FILTER_VALIDATE_URL)) {
+            $apActivity = $this->activityRepository->findByObjectId($url);
+            if (!$isApRequest && null !== $apActivity && Message::class !== $apActivity['type']) {
+                $this->logger->debug('Found activity with url {u}: {t} - {id}', [
+                    'u' => $node->getUrl(),
+                    't' => $apActivity['type'],
+                    'id' => $apActivity['id'],
+                ]);
+                /** @var Entry|EntryComment|Post|PostComment $entity */
+                $entity = $this->entityManager->getRepository($apActivity['type'])->find($apActivity['id']);
+
+                return new HtmlElement('div', contents: $this->renderInlineEntity($entity));
+            }
         }
 
         $renderTarget = $this->config->get('kbin')[MarkdownConverter::RENDER_TARGET];
diff --git a/src/Markdown/Event/BuildCacheContext.php b/src/Markdown/Event/BuildCacheContext.php
index 8e7222129..b175e9b45 100644
--- a/src/Markdown/Event/BuildCacheContext.php
+++ b/src/Markdown/Event/BuildCacheContext.php
@@ -17,7 +17,7 @@ class BuildCacheContext
 
     public function __construct(
         private readonly ConvertMarkdown $convertMarkdownEvent,
-        private readonly Request $request,
+        private readonly ?Request $request,
     ) {
         $this->addToContext('content', $convertMarkdownEvent->getMarkdown());
         $this->addToContext('target', $convertMarkdownEvent->getRenderTarget()->name);
diff --git a/src/Utils/UrlUtils.php b/src/Utils/UrlUtils.php
index 2e9ceb37c..b3750b20e 100644
--- a/src/Utils/UrlUtils.php
+++ b/src/Utils/UrlUtils.php
@@ -8,8 +8,11 @@
 
 class UrlUtils
 {
-    public static function isActivityPubRequest(Request $request): bool
+    public static function isActivityPubRequest(?Request $request): bool
     {
+        if (null === $request) {
+            return true;
+        }
         $acceptValue = $request->headers->get('Accept', default: 'html');
 
         return str_contains($acceptValue, 'application/activity+json')