diff --git a/components/Media/Media.php b/components/Media/Media.php
index 21910a1f36..7b055c626f 100644
--- a/components/Media/Media.php
+++ b/components/Media/Media.php
@@ -22,6 +22,7 @@ namespace Component\Media;
 use App\Core\Cache;
 use App\Core\Event;
 use App\Core\Module;
+use App\Util\Common;
 use App\Util\Nickname;
 
 class Media extends Module
@@ -39,7 +40,9 @@ class Media extends Module
 
     public function onEndTwigPopulateVars(array &$vars)
     {
-        $vars['user_avatar'] = self::getAvatarUrl();
+        if (Common::user() != null) {
+            $vars['user_avatar'] = self::getAvatarUrl();
+        }
         return Event::next;
     }
 
diff --git a/components/Media/Utils.php b/components/Media/Utils.php
index 0297f47a1f..425f8e4c40 100644
--- a/components/Media/Utils.php
+++ b/components/Media/Utils.php
@@ -52,7 +52,6 @@ abstract class Utils
             'file_hash' => $hash,
             'actor_id'  => $actor_id,
             'mimetype'  => $sfile->getMimeType(),
-            'size'      => $sfile->getSize(),
             'title'     => $title ?: _m('Untitled attachment'),
             'is_local'  => $is_local,
         ]);
@@ -137,12 +136,14 @@ abstract class Utils
         }
     }
 
-    public static function getAvatarUrl(string $nickname = null)
+    public static function getAvatarUrl(?string $nickname = null)
     {
         if ($nickname == null) {
             $user = Common::user();
             if ($user != null) {
                 $nickname = $user->getNickname();
+            } else {
+                throw new Exception('No user is logged in and no avatar provided to `getAvatarUrl`');
             }
         }
         return Cache::get('avatar-url-' . $nickname, function () use ($nickname) {