Hi Harry,
To better help you with your concern about the missing world in the game Minecraft, we recommend that you follow the steps below:
How to recover missing Minecraft world:
- Click the start button and search %appdata%.
- Find and enter the .minecraft folder.
- Find the saves folder and right-click it, there should be an option called restore previous versions.
If the issue persists after doing the steps provided above, we recommend that you submit a request regarding this matter on this link.
Keep us posted.