diff --git a/static/js/document.js b/static/js/document.js
index c2745c6b6..06e8720aa 100644
--- a/static/js/document.js
+++ b/static/js/document.js
@@ -3753,7 +3753,11 @@ import { bindMenuDismiss, dismissOrRemove } from './escMenuStack.js';
         await _streamEmailBodyText(textarea, newBody);
         if (uiModule) uiModule.showToast(`AI draft inserted (${data.model_used || 'AI'})`);
       } else {
-        if (uiModule) uiModule.showError(data.error || 'Failed to generate reply');
+        const rawMsg = data.error || 'Failed to generate reply';
+        const msg = /empty response/i.test(rawMsg)
+          ? 'AI reply failed: AI returned empty response.'
+          : rawMsg;
+        if (uiModule) uiModule.showError(msg);
       }
     } catch (e) {
       if (uiModule) uiModule.showError('Failed to generate AI reply');
diff --git a/static/js/emailInbox.js b/static/js/emailInbox.js
index 7f0e24773..17b1d1dc2 100644
--- a/static/js/emailInbox.js
+++ b/static/js/emailInbox.js
@@ -804,7 +804,10 @@ async function _openEmail(em, itemEl, preloadedData = null, mode = 'reply', note
           if (result.success && result.reply) {
             aiSuggestedBody = _cleanAiReplyText(result.reply);
           } else {
-            const _msg = result.error || 'AI reply could not be generated';
+            const _rawMsg = result.error || 'AI reply could not be generated';
+            const _msg = /empty response/i.test(_rawMsg)
+              ? 'AI returned empty response.'
+              : _rawMsg;
             console.error('AI reply generation failed:', _msg);
             import('./ui.js').then(m => m.showError && m.showError('AI reply failed: ' + _msg)).catch(() => {});
             return;