The mesh has a skeleton. SceneSerializer.Serialize works fine but GLTFExporter causes the meshes to look a little strange and the GLB files either (1) don’t render or (2) appear as they do when GLTFExporter completes (the screenshot below)
The specific error seems to be: “Invalid recursive node hiearchy”
This happens on the latest alpha build.
Playground #1 (showing the original & strange-looking scene): https://playground.babylonjs.com/#N4IA1H#1
Playground #2 (showing the exception when re-importing): https://playground.babylonjs.com/#L7LYWA#2
The playgrounds might take about a minute to load, these are not small GLB files. These GLB files were exported from Blender, but I’ve seen similar results when exporting from Maya instead.