Troubleshooting

The simulation won’t start

1. Check the Output console — if the compile failed, the error is there, with file and line. See reading compile errors.
2. A circuit verifier warning (e.g. an LED without a series resistor in electrical mode) blocks the run on purpose — fix the flagged wiring.
3. First run of a session compiles cold and can take a while on the big toolchains (ESP-IDF); later runs are much faster. Give the first one time before assuming it hung.

It runs, but nothing happens

• Is the right board selected in the toolbar’s board selector?
• Open the serial monitor — a firmware that crashed or is waiting for input tells you there.
• Right-click parts to confirm their properties (a NeoPixel strip set to 0 LEDs draws exactly nothing).

The page itself misbehaves

• Velxio wants a desktop Chromium or Firefox, reasonably current.
• Hard-reload (Ctrl+Shift+R) after updates — a stale cached bundle can pair badly with a fresh backend.
• Browser extensions that touch WebAssembly, canvas or WebSockets (aggressive privacy blockers) can break the emulators — try an incognito window.

Web flash doesn’t see my board

• Use Chrome or Edge — Firefox/Safari don’t ship the browser serial API.
• Close every other program using the port (serial monitors, IDEs).
• Try another cable — charge-only USB cables are the classic trap.

WiFi examples can’t connect

• The SSID is exactly Velxio-GUEST, open, no password.
• Watch the serial monitor for the WiFi stack’s own progress lines (wifi:connected, got ip) to see which step fails.

Still stuck?

Ask the AI assistant with your project open — it reads the same errors you do. For bugs, reach the team via the Help menu, Discord, or GitHub.