- Make sure you have installed the addon following the installation guide you can find here :ref:`installation`.
- Make sure you have installed the addon from the zip file as described in the installation guide :ref:`installation`.
- Make sure you have downloaded the latest version of the addon, the list of updates can be found here :ref:`updates_log`
This operation can be undone simply by pressing Ctrl+Z. If you have already closed Blender or saved the file, you can find the autosave via the File -> Recover --> Autosave menu.