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Troubleshooting

If something isn't working right, start here. These are the most common issues and their fixes. For all of these, running deja logs is a great first step — it shows you exactly what the server is doing (or what went wrong).

Server Not Connecting to CommandStation

Symptoms: deja status shows no serial port, or the Throttle app says "Disconnected."

  1. Check the USB cable — make sure it's plugged in at both ends. Try a different USB port on the computer.
  2. Run deja status — look under Connections for a serial port like /dev/ttyUSB0 or /dev/tty.usbmodem*. If none is listed, the server can't see the CommandStation.
  3. Restart the server — deja restart will re-scan for serial ports and try to connect again.
  4. Try unplugging and replugging the USB cable, then restart the server.

Serial Port Permission Denied (Linux / Raspberry Pi)

Symptoms: The server starts but can't open the serial port. Logs show a "permission denied" error.

Run this command once to add your user to the dialout group:

sudo usermod -a -G dialout $USER

Then log out and log back in (or reboot). This only needs to be done once — after that, the server will always have access.

Server Won't Start

Symptoms: deja start shows an error or the server exits immediately.

  1. Check Node.js version: Run node --version — you need v20 or later. If you need to upgrade, visit nodejs.org.
  2. Check the logs: Run deja logs to see what error the server reported.
  3. Reinstall: Run the installer again — it downloads a fresh copy and reconfigures: 
    curl -fsSL https://install.dejajs.com | bash

Firebase Connection Errors

Symptoms: Logs show Firebase or Firestore errors. The Throttle and Cloud apps can't see the server.

Your Firebase credentials may be missing or incorrect. They live in ~/.deja/.env.

  1. Open the Cloud app and go to Settings → View Local Environment Configuration.
  2. Compare those values with what's in your ~/.deja/.env file.
  3. If they don't match, update the .env file and restart: deja restart.

Or re-run the installer to reconfigure automatically.

Subscription Issues

"Subscription inactive"

Your subscription may have expired or been canceled. Visit dejajs.com to check your account status and renew.

The server allows a 48-hour grace period when it can't reach the internet — if your subscription was active within the last 48 hours, the server will continue running using its cached status.

"Cannot verify subscription"

The server needs to verify your subscription online periodically. If it can't reach Firebase and the cached verification is older than 48 hours, it will stop.

Connect the computer to the internet and restart the server: deja restart.

deja Command Not Found

If the terminal says deja: command not found after installation:

  1. Open a new terminal window — the installer added deja to your PATH, but the current terminal may not have picked it up yet.
  2. Or reload your shell config: 
    source ~/.zshrc    # if using zsh
source ~/.bashrc   # if using bash
  3. Or run it directly: 
    ~/.deja/bin/deja status

Still Stuck?

If none of the above fixes your issue:

  1. Run deja logs -n 100 and look for error messages near the bottom.
  2. Run deja status and note any warnings.
  3. Check the DEJA.js community for help from other users.