diff --git a/lib/Controller/ApiController.php b/lib/Controller/ApiController.php
index 8e6f61fa..8ecdba26 100644
--- a/lib/Controller/ApiController.php
+++ b/lib/Controller/ApiController.php
@@ -178,23 +178,27 @@ class ApiController extends Controller {
         }
 
         // Run actual query
-        $list = $this->timelineQuery->getDays(
-            $folder,
-            $uid,
-            $recursive,
-            $archive,
-            $this->getTransformations(),
-        );
+        try {
+            $list = $this->timelineQuery->getDays(
+                $folder,
+                $uid,
+                $recursive,
+                $archive,
+                $this->getTransformations(),
+            );
 
-        // Preload some day responses
-        $this->preloadDays($list, $folder, $recursive, $archive);
+            // Preload some day responses
+            $this->preloadDays($list, $folder, $recursive, $archive);
 
-        // Add subfolder info if querying non-recursively
-        if (!$recursive) {
-            array_unshift($list, $this->getSubfoldersEntry($folder));
+            // Add subfolder info if querying non-recursively
+            if (!$recursive) {
+                array_unshift($list, $this->getSubfoldersEntry($folder));
+            }
+
+            return new JSONResponse($list, Http::STATUS_OK);
+        } catch (\Exception $e) {
+            return new JSONResponse(["message" => $e->getMessage()], Http::STATUS_INTERNAL_SERVER_ERROR);
         }
-
-        return new JSONResponse($list, Http::STATUS_OK);
     }
 
     /**
@@ -247,15 +251,19 @@ class ApiController extends Controller {
         }
 
         // Run actual query
-        $list = $this->timelineQuery->getDay(
-            $folder,
-            $uid,
-            $day_ids,
-            $recursive,
-            $archive,
-            $this->getTransformations(),
-        );
-        return new JSONResponse($list, Http::STATUS_OK);
+        try {
+            $list = $this->timelineQuery->getDay(
+                $folder,
+                $uid,
+                $day_ids,
+                $recursive,
+                $archive,
+                $this->getTransformations(),
+            );
+            return new JSONResponse($list, Http::STATUS_OK);
+        } catch (\Exception $e) {
+            return new JSONResponse(["message" => $e->getMessage()], Http::STATUS_INTERNAL_SERVER_ERROR);
+        }
     }
 
     /**
diff --git a/lib/Db/TimelineQueryFaces.php b/lib/Db/TimelineQueryFaces.php
index a0b12231..ddb4b3bf 100644
--- a/lib/Db/TimelineQueryFaces.php
+++ b/lib/Db/TimelineQueryFaces.php
@@ -10,10 +10,10 @@ use OCP\Files\Folder;
 trait TimelineQueryFaces {
     protected IDBConnection $connection;
 
-    public function transformFaceFilter(IQueryBuilder &$query, string $userId, string $faceName) {
+    public function transformFaceFilter(IQueryBuilder &$query, string $userId, string $faceStr) {
         // Get title and uid of face user
-        $faceNames = explode('/', $faceName);
-        if (count($faceNames) !== 2) return;
+        $faceNames = explode('/', $faceStr);
+        if (count($faceNames) !== 2) throw new \Exception("Invalid face query");
         $faceUid = $faceNames[0];
         $faceName = $faceNames[1];
 
@@ -23,7 +23,7 @@ trait TimelineQueryFaces {
             ->where($query->expr()->eq('user_id', $sq->createNamedParameter($faceUid)))
             ->andWhere($query->expr()->eq('title', $sq->createNamedParameter($faceName)))
             ->executeQuery()->fetchOne();
-        if (!$id) return;
+        if (!$id) throw new \Exception("Unknown person: $faceStr");
 
         // Join with cluster
         $query->innerJoin('m', 'recognize_face_detections', 'rfd', $query->expr()->andX(
diff --git a/lib/Db/TimelineQueryTags.php b/lib/Db/TimelineQueryTags.php
index d89f1714..278bde8b 100644
--- a/lib/Db/TimelineQueryTags.php
+++ b/lib/Db/TimelineQueryTags.php
@@ -22,7 +22,7 @@ trait TimelineQueryTags {
     public function transformTagFilter(IQueryBuilder &$query, string $userId, string $tagName) {
         $tagId = $this->getSystemTagId($query, $tagName);
         if ($tagId === FALSE) {
-            $tagId = 0; // cannot abort here; that will show up everything in the response
+            throw new \Exception("Tag $tagName not found");
         }
 
         $query->innerJoin('m', 'systemtag_object_mapping', 'stom', $query->expr()->andX(