Hi there ! I'm currently making an in-editor tool that is creating, parenting, deleting children inside a prefab. But no matter what method I call before or after editing my object, changes are lost when I quit the prefab mode. To test faster, I've unchecked the auto save option, so I guess it will work when the save button will be activated. I've tried before edition: Undo.RecordObject(transform, "update branches"); and then after: PrefabUtility.RecordPrefabInstancePropertyModifications(transform); EditorUtility.SetDirty(transform); EditorSceneManager.MarkSceneDirty(SceneManager.GetActiveScene()); Any advice ? It's quite hard to find clear indications about this new workflow anywhere on the web, I'm kinda lost searching for clues... Thanks !