diff --git a/public/player.js b/public/player.js
index bd35b6d..b3d1c55 100644
--- a/public/player.js
+++ b/public/player.js
@@ -296,4 +296,4 @@ function openNow() {
   updateNow(); syncUI();
 }
 // Tell the page how tall the player is, so buttons that float at the bottom (Home, Ask) sit above it instead of covering it.
-{ const pe = $('#player'); if (pe && window.ResizeObserver) new ResizeObserver(() => document.documentElement.style.setProperty('--playerh', (pe.hidden ? 0 : pe.offsetHeight) + 'px')).observe(pe); }
+if (typeof ResizeObserver === 'function' && typeof document !== 'undefined') { const pe = document.getElementById('player'); if (pe) new ResizeObserver(() => document.documentElement.style.setProperty('--playerh', (pe.hidden ? 0 : pe.offsetHeight) + 'px')).observe(pe); }
diff --git a/public/sw.js b/public/sw.js
index c6dadeb..375c2a7 100644
--- a/public/sw.js
+++ b/public/sw.js
@@ -1,5 +1,5 @@
 // App-shell cache only; Seafile/API traffic always goes to the network.
-const CACHE = 'hub-v86';
+const CACHE = 'hub-v87';
 const SHARE = 'hub-share'; // files shared into the app from other apps, held until the person picks a folder
 const SHELL = ['/icon.svg', '/manifest.webmanifest', '/icons/icon-192.png', '/icons/apple-touch-icon.png'];