Hi, there seem to be some issues with Babylon Playground ATM.
All examples work fine in Playground 4.2.0-rc.3 however in any other Babylon version they crash with the error: Unable to import meshes from ...: importMesh of unknown
It also seems to affect SceneLoader.ImportMesh and AssetContainer.
I noticed that I also got a warning for all versions that are broken: babylon.js:16 BJS - [21:42:02]: Unable to find a plugin to load .gltf files. Trying to use .babylon default plugin. To load from a specific filetype (eg. gltf) see: http://doc.babylonjs.com/how_to/load_from_any_file_type
I have tested both Chrome and MS Edge and it’s the same issue in both.
We may have found an issue related to this one actually (It is because of the Unity Exporter plugin)
Can you try in a couple of hours (or tomorrow morning as I guess you are sleeping now ;))
Still get this warning (and an error afterwards): Unable to find a plugin to load .gltf files. Trying to use .babylon default plugin. To load from a specific filetype (eg. gltf)