The Sims 3 world editor needed a corresponding version. Different versions of the editor may have different functions, so you need to use the corresponding version to edit. If you are using the version of The Sims 3, it is recommended to confirm whether the game has installed the world editor. If the game does not have the world editor installed, you can download or install the update package to install the version. Once the world editor was installed, one would need to choose the corresponding game version to edit it. Each version had its own unique world editor, so one had to choose the corresponding version to use the correct editor function. For example, if you were using the latest version of The Sims 3 (19A), you would need to download and install the latest world editor (19A) to edit it. If you are using the earlier version of The Sims 3 (10), you will need to download and install the earlier version of the World Editor (10) to edit it.