Failed to read past end of steam

So I started my server after the hosting computer was shutdown improperly, and i noticed this error:
Error loading save (server/rust-server/proceduralmap.6000.16767543.142.map.sav): Failed to read past end of stream.

What does it mean and how can i fix it?

 

Yep. It apparently is 0 bytes.
But why did that affect all 4 (0-3) backups?

Thanks for being quick btw.