Index: src/assets/js/mod/download.js
===================================================================
--- src/assets/js/mod/download.js	(revision a8364eebcd86a4ed81e5828536e10f189505da2e)
+++ src/assets/js/mod/download.js	(revision a66266d23ff7d4cf2f10b82f0aaefa77102e6848)
@@ -13,4 +13,4 @@
 function run() {
         // Auto-start de download (zelfde-origin attachment-link).
-        setTimeout(function(){ try { window.location.href = (pageData().fileUrl || ''); } catch(e){} }, 600);
+        setTimeout(function(){ try { var u = pageData().fileUrl; if (u) window.location.href = u; } catch(e){} }, 600);
 }