diff --git a/App.tsx b/App.tsx
index a1c078a..a18c0c1 100644
--- a/App.tsx
+++ b/App.tsx
@@ -162,7 +162,7 @@ const App: React.FC = () => {
             const shouldReopen = role === 'user' && t.status === TicketStatus.RESOLVED;
             return { 
                 ...t, 
-                messages: [...t.messages, newMsg],
+                messages: [...(t.messages || []), newMsg], // FIX: Ensure array fallback
                 status: shouldReopen ? TicketStatus.OPEN : t.status
             };
         })