diff --git a/web/ui/app.js b/web/ui/app.js
index 9a4cac1..6d3ed62 100644
--- a/web/ui/app.js
+++ b/web/ui/app.js
@@ -175,6 +175,11 @@ async function doExtract() {
   try {
     const resp = await fetch(`${API}/extract?dir=${encodeURIComponent(isoDir)}&out=${encodeURIComponent(wavDir)}`);
     const data = await resp.json();
+    if (data.error) {
+      status.textContent = data.error;
+      status.style.color = 'var(--accent)';
+      return;
+    }
     status.textContent = data.message || 'Extraction complete';
     status.style.color = 'var(--green)';
   } catch (e) {