Hello,
With the previous version of Unity we used code to store all the scene with the Undo API, we used : Undo.RegisterSceneUndo(string).
With the last version of Unity this is deprecated and we cannot manage how to use the new Undo API.
We have to store the complete state of an object (transform, components, mesh construction destruction, colliders construction destruction) and all of his transform childs. So we used “Undo.RegisterFullObjectHierarchyUndo” but it is not working properly.
Thanks for your help,