Update app.py

app.py

@@ -34,4 +34,6 @@ try:
 
 except FileNotFoundError:
     st.error(f"Error: Could not find the file '{html_file_path}'.")
-    st.warning("Please make sure
+    st.warning("Please make sure the `index.html` file (containing the Three.js code) is in the same directory as this `app.py` script.")
+except Exception as e:
+    st.error(f"An error occurred while reading or embedding the HTML file: {e}")