"Content Not Ready" in Fortnite Save the World

If you see this error try these steps to resolve the issue:

1. Exit the Epic Games Launcher
2. Press Windows + R
3. Type "%localappdata%", and press Enter
4. Delete the entire EpicGamesLauncher folder
5. Delete the entire FortniteGame folder
6. Re-launch the Epic Games Launcher
7. Try running Save the World