Doctor reference

Window → General → Loom Doctor is the first stop when something isn’t working. It runs a series of self-checks and reports green / yellow / red for each. This page is the reference for what each check means.

Native plugin loaded

What it checks: That the native plugin loaded successfully for your platform.

Red means: Either the Unity package doesn’t include a native binary for your platform, or Unity failed to load the one that’s there.

Fix: Reinstall the Unity package, then restart Unity. If the problem persists, your platform may not be supported in this release — see the Install page for supported platforms.

ABI version match

What it checks: That the native plugin and the C# package are from the same Loom release.

Red means: They’re from different releases — your install is inconsistent.

Fix: Delete <Project>/Library/PackageCache/com.loomgui@*/ and restart Unity. The package will reinstall on the next launch.

WS port bound

What it checks: That the native plugin’s WebSocket server has bound a port.

Red means: The native plugin failed to bind any port. Likely a system- level problem (firewall, sandbox).

Fix: Check the Unity Editor log (Console → … → Open Editor Log) for errors around plugin initialization. Restart Unity.

UI directory present

What it checks: That <ProjectRoot>/UI/ exists and contains a package.json.

Red means: No UI folder for Loom to use.

Fix: Scaffold a UI folder (Your first screen) or copy your existing Solid app to <ProjectRoot>/UI/.

npm dependencies installed

What it checks: That <ProjectRoot>/UI/node_modules/@loomgui/bridge and @loomgui/vite-plugin exist.

Red means: npm install hasn’t run, or the bundled tarballs aren’t linked.

Fix: Run Loom → Sync UI Dependencies from the menu.

Dev server alive

What it checks (Editor only): That Vite is reachable.

Yellow during Play startup is normal — Vite is still starting. Red outside of Play startup means Vite died or was killed by something else.

Fix: Run Loom → Restart Dev Server.