diff --git a/lib/Activity/ActivityManager.php b/lib/Activity/ActivityManager.php
index f5a9e937a..efd2ea48e 100644
--- a/lib/Activity/ActivityManager.php
+++ b/lib/Activity/ActivityManager.php
@@ -302,6 +302,8 @@ class ActivityManager {
 		try {
 			$object = $this->findObjectForEntity($objectType, $entity);
 		} catch (DoesNotExistException $e) {
+			\OC::$server->getLogger()->error('Could not create activity entry for ' . $subject . '. Entity not found.', $entity);
+			return null;
 		} catch (MultipleObjectsReturnedException $e) {
 			\OC::$server->getLogger()->error('Could not create activity entry for ' . $subject . '. Entity not found.', $entity);
 			return null;
diff --git a/lib/Activity/DeckProvider.php b/lib/Activity/DeckProvider.php
index d6f2fc4d9..1a95f6940 100644
--- a/lib/Activity/DeckProvider.php
+++ b/lib/Activity/DeckProvider.php
@@ -104,7 +104,7 @@ class DeckProvider implements IProvider {
 		];
 		$event->setAuthor($author);
 		if ($event->getObjectType() === ActivityManager::DECK_OBJECT_BOARD) {
-			if ($event->getObjectName() === '') {
+			if (isset($subjectParams['board']) && $event->getObjectName() === '') {
 				$event->setObject($event->getObjectType(), $event->getObjectId(), $subjectParams['board']['title']);
 			}
 			$board = [
@@ -116,7 +116,7 @@ class DeckProvider implements IProvider {
 			$params['board'] = $board;
 		}
 
-		if ($event->getObjectType() === ActivityManager::DECK_OBJECT_CARD) {
+		if (isset($subjectParams['card']) && $event->getObjectType() === ActivityManager::DECK_OBJECT_CARD) {
 			if ($event->getObjectName() === '') {
 				$event->setObject($event->getObjectType(), $event->getObjectId(), $subjectParams['card']['title']);
 			}