diff --git a/app.js b/app.js
index cfe068f..9f717e7 100644
--- a/app.js
+++ b/app.js
@@ -1796,13 +1796,22 @@ function openFileViewer({ url, blob, mime }, filename, relpath) {
     const isImage = (mime || '').startsWith('image/');
     const isPdf = (mime || '').includes('pdf') || /\.pdf$/i.test(filename);
 
+    console.log('[FILE] openFileViewer:', {filename, mime, isPdf, pdfjs: typeof pdfjs, blobSize: blob.size});
+
     if (isPdf && typeof pdfjs !== 'undefined') {
+        console.log('[FILE] → PDF-Viewer aufrufen');
         openPdfViewer(blob, filename, relpath);
         return;
     }
 
+    if (isPdf && typeof pdfjs === 'undefined') {
+        console.warn('[FILE] PDF.js ist NICHT geladen!');
+        showToast('⚠️ PDF.js nicht verfügbar, Download stattdessen', 'error');
+    }
+
     if (!isImage) {
         // Alles außer Bildern + PDFs: Download
+        console.log('[FILE] → Download-Fallback');
         const a = document.createElement('a');
         a.href = url;
         a.download = filename || 'download';