Update app.py

app.py

@@ -189,8 +189,10 @@ async def process_url(url, depth, progress_callback):
         logger.error(f"Error in process_url: {str(e)}")
         return f"An error occurred: {str(e)}"
 
+# App layout
 # App layout
 app.layout = dbc.Container([
+    dcc.Store(id='pdf-store'),  # Add this line at the beginning of the layout
     dbc.Navbar(
         dbc.Container([
             html.A(