Originally posted by The Grey Hawk:

Originally posted by Zig:

now u know backup is very important...

Or just ♥♥♥♥♥♥♥ dont let it happen?
Am i supposed to backup every single game i play...

The game is in Early Access, which means it's still in beta.
It's not the first game where savefiles can get corrupt or overwritten by older cloud-saves.
It even happens in released AAA-titles (like skyrim for example).