Loom Doctor

Loom -> Doctor is the first stop when setup or startup fails. It checks the environment Unity can actually see and reports the result in the Unity Console.

Loom -> Status Window shows the same checks in a dockable window.

Node.js found

Checks that node is available to the Unity Editor process.

If red, install Node.js 20+ or launch Unity from an environment where Node is on PATH.

npm found

Checks that npm is available. Loom needs npm to install UI dependencies and run production UI builds.

If red, reinstall Node.js or fix PATH for the Unity process.

Vite dev server

Checks whether the UI dev server can start and respond.

If red, run Loom -> Restart Dev Server and inspect the Unity Console for npm or Vite output.

Native plugin

Checks that the platform plugin for your OS is present.

If red after installing or upgrading Loom, restart Unity. If it stays red, reinstall the package.

Firefox DevTools

Checks whether Loom can open Firefox for browser DevTools.

If red, install Firefox or debug without DevTools.

Generated bridge types

Checks whether generated UI bridge files exist and look current.

If red, run:

Loom -> Regenerate Types

Then restart the dev server.

Build cache

Checks cached build/runtime files that can become stale after package upgrades.

If red after an upgrade, restart Unity and rerun the check.