I am curious to find out how the map was corrupted, because it should have detected this kind of map corruption on saving, but it would take me several hours to fix any of the saves (with possibility of not being able to do it at all), I am sorry.

I just hoped that it would be possible to ...

Hi!
So I wanted to load the map I'm playing on, but I've found that Factorio can't load any of my recent saves:
https://drive.google.com/drive/folders/1V3T4SsjRTWCSX13bJXu_taCDp9WgmPla?usp=sharing
M6:
Corrupt map: unknown tile 0.
Autosave 1:
Corrupt map: unknown tile 0.
Autosave 2:
Corrupted map ...

Thanks for the report.
One of the steam engines on chunk {8, 18} has been saved improperly to list of active entities ... when I commute, I'll think about what would have to get corrupted for that to happen without game crashing instantly, but it looks like random game state corruption.

Hi ...

I almost finished setting up a production line for making Assembling machine 3, when the game crashed during autosave. (The game freezed when the autosave progress bar reached 100%, then crashed after a few seconds)

After this I launched Factorio again, and tried to load the autosaves.
_autosave3 ...