The dashboard will not open
Check whether Udon is running, recover local access, and trace LAN, Tailscale, or certificate failures.
If your browser cannot connect to Udon, start on the Mac running it. Keep that local browser open while checking remote access, so a network change does not leave you disconnected.
Check Udon on the Mac
Open the Udon menu bar panel, turn on Enable Udon, then choose Open Udon. If the menu
bar app is missing, run udond status in Terminal using the macOS account that installed Udon.
Run udond start if it is stopped; if it reports running but the page still fails, try
udond restart once. If the shell can't find udond, use its full path,
/Applications/Udon.app/Contents/MacOS/udond.
The default local address is https://127.0.0.1:4443. Open Udon uses your configured listen
address and port, including IPv6. A permission screen means the dashboard is reachable; follow
Full Disk Access troubleshooting or the
Admin Privileges instructions.
Check the address and certificate
Udon normally uses a self-signed certificate. A browser warning at your own Mac's Udon address is expected; confirm the address before trusting it. A connection refusal or timeout needs the remaining checks.
If HTTPS fails locally, inspect ~/Library/Application Support/sh.udon/udond.log. The
starting udond entry records the scheme, host, and port. A certificate-loading or generation
error can make Udon fall back to HTTP. Correct the certificate/key paths or permissions named
in the log and restart Udon. The install guide lists the config
and log locations.
Try the Mac's LAN address
From another device on the same network, use the Mac's current IP address and Udon's port,
for example https://192.168.1.20:4443. Find the IP in Settings → Network on the working
local dashboard. localhost on the other device refers to that device.
If the IP works but the hostname fails, check name resolution. If only local access works,
check the Mac's firewall and network isolation. A custom server.host set to 127.0.0.1
accepts local connections only; Udon's default, 0.0.0.0, listens on all interfaces.
If other devices lose the dashboard while the Mac sits idle, it may be asleep. Turn on Keep Mac awake in the menu bar panel so it doesn't sleep on its own; see Keep Mac awake.
Check Tailscale separately
In Settings → Tailscale, confirm Connected. Finish Sign in → Open sign-in page if needed, and connect the other device to the same tailnet. Check that Block incoming connections is off if you intend to allow access.
Try Reachable on your tailnet first. For HTTPS without a browser warning, enable Serve with a trusted certificate and use the exact Trusted URL, without adding Udon's port. If only that URL fails, keep the error from the Serve operation. See Network & remote access for the controls.
Confirm recovery by signing in from the device and address that originally failed. If it still fails, email [email protected] with your Udon/macOS versions, browser error, which local/LAN/Tailscale checks worked, and relevant log lines. Remove credentials and tokens before sending.