diff --git a/ActivityPubPlugin.php b/ActivityPubPlugin.php
index fb53c6b..6e517d7 100755
--- a/ActivityPubPlugin.php
+++ b/ActivityPubPlugin.php
@@ -139,7 +139,7 @@ class ActivityPubPlugin extends Plugin
         }
         try {
             return Activitypub_notice::create_notice(
-                ActivityPub_explorer::get_profile_from_url($res->attributedTo),
+                ActivityPub_explorer::get_profile_from_url($res['attributedTo']),
                 $res->id,
                 $res->url,
                 $res->content,
diff --git a/utils/explorer.php b/utils/explorer.php
index c2ff051..f8baa32 100755
--- a/utils/explorer.php
+++ b/utils/explorer.php
@@ -60,7 +60,7 @@ class Activitypub_explorer
             $actor_profile = $discovery->lookup($url);
             return $actor_profile[0];
         } catch (Exception $e) {
-            throw new Exception('Invalid Actor: '.$url);
+            throw new Exception('Invalid Actor.');
         }
         unset($discovery);
     }
@@ -77,7 +77,7 @@ class Activitypub_explorer
     public function lookup($url)
     {
         if (in_array($url, ACTIVITYPUB_PUBLIC_TO)) {
-            throw new Exception ('Empty Actor URL.');
+            return [];
         }
 
         common_debug('ActivityPub Explorer: Started now looking for '.$url);