Please try the following steps:
- If this error occurs when backing up and restoring data, check that your USB drive is properly connected to your console and try again.
- If this error occurs when reading the save data, copy the save data to PlayStation®Plus online storage or a USB drive, then download it to your PlayStation®4 console.
- If the problem still persists, delete the relevant application and then reinstall it.
- Try creating new save data.