If you have come across the following message:
Save file not compatible with this version of No Way Home. Please update No Way Home via the App Store to play this save.
It is due to the latest save data on your account being played on a more recent version of No Way Home than you currently have installed on your device. This could have occurred for several reasons, the most common being that you have more than one device and a different version of No Way Home on each.
The solution to resolve this is to simply head over to Apple Arcade and make sure you are running the latest version of No Way Home across all of your devices.