Crazy problem: a newer version of the game has saved this level. It cannot be loaded

I created my survival World in 1.8 on an Android Device.

I uploaded it on Realms because I needed to clean my telephone, so I wanted to upload the world, uninstall everything and download it again to play offline.

When I try to play online on Realms, I log normally.

But when I try to play the downloaded offline backup the game tells me " a newer version of the game has saved this level. It cannot be loaded" which is NOT possibile, since the version is still 1.8 and I never played other prior or later versions ever.

I tried on multiple devices and the situation is always the same.