`EditorApplication.hierarchyWindowItemOnGUI` must be updated to [`EditorApplication.hierarchyWindowItemByEntityIdOnGUI`](https://docs.unity3d.com/6000.5/Documentation/ScriptReference/EditorApplication-hierarchyWindowItemByEntityIdOnGUI.html) in order to support Unity 6.5+.
EditorApplication.hierarchyWindowItemOnGUImust be updated toEditorApplication.hierarchyWindowItemByEntityIdOnGUIin order to support Unity 6.5+.