diff --git a/lib/Data.php b/lib/Data.php
index e8fa54492..c83440725 100644
--- a/lib/Data.php
+++ b/lib/Data.php
@@ -519,7 +519,7 @@ public function getActivitySince(string $user, int $since, bool $byOthers) {
 			$query->andWhere($query->expr()->neq('user', $nameParam));
 		}
 
-		return $query->executeQuery()->fetch();
+		return $query->executeQuery()->fetch() ?: [];
 	}
 
 	/**
diff --git a/lib/FilesHooks.php b/lib/FilesHooks.php
index 8f7e75f78..d5d31c2b2 100644
--- a/lib/FilesHooks.php
+++ b/lib/FilesHooks.php
@@ -826,7 +826,7 @@ public function unShareSelf(IShare $share) {
 		if (in_array($share->getNodeType(), ['file', 'folder'], true)) {
 			if ($share->getShareType() === IShare::TYPE_GROUP) {
 				$this->unshareFromSelfGroup($share);
-			} else {
+			} elseif ($share->getShareType() === IShare::TYPE_USER) {
 				$this->unshareFromUser($share);
 			}
 		}
diff --git a/tests/FilesHooksTest.php b/tests/FilesHooksTest.php
index 00dfbff0d..b1ebafc83 100644
--- a/tests/FilesHooksTest.php
+++ b/tests/FilesHooksTest.php
@@ -962,6 +962,8 @@ public function testLeaveShare(): void {
 			->willReturn('file');
 		$share->method('getSharedWith')
 			->willReturn('with');
+		$share->method('getShareType')
+			->willReturn(IShare::TYPE_USER);
 
 		$this->settings->expects($this->exactly(3))
 			->method('getUserSetting')