The Mixamo "X Bot.fbx" required by demos 04-skinned-fbx.html and
05-skinned-realtime.html is intentionally not redistributed here.

Download your own from https://mixamo.com (FBX Binary, T-Pose,
Without Skin) and place it here as "X Bot.fbx" if you want to
run those demos locally. See examples/three.js/README.md in the
repo for context.