sceneLoadedCallback scene parameter usage

[Observablerxjs]

I managed to make it work finally

The error was that the serialization was being executed before the scene was actually ready to be serialized. The solution was to place it inside a executeWhenReady block

onSceneLoaded(sceneFile: File, babylonScene: BABYLON.Scene)
{
   /*WRONG*/
   const serializedScene = BABYLON.SceneSerializer.Serialize(babylonScene);
  
   /*CORRECT*/
   babylonScene.executeWhenReady(() =>
   {
      const serializedScene = BABYLON.SceneSerializer.Serialize(babylonScene);
      const jsonObj = JSON.stringify(serializedScene);
      // broadcast object via socket.io here
    });
    .
    .
    .
}

Thank you again for your help @aWeirdo and @Evgeni_Popov