Since my original post I encountered the same problem. It happened with the assemblers this time. I didn't report this, because I didn't loose any significant progress and also it was quite peculiar that I encountered this again in this short amount of time. So I dug deeper and I'd like to share my ...

Wow, thank you very much for looking into it. I can consider myself lucky that it happened in a place like this and you were able to find it.

Yeah, I know about the cosmic ray/particle "risk". This is why ECC RAM is a thing. I heard about the correlation myself also.

Thank you very much again! You ...

I'll try to recreate what I did in those 4 hours (I wanted to do that anyway if the save is not fixable) and I'll just set the number of autosaves higher and we'll see if I can pinpont something usable for You.
Maybe I'll not find anything, who knows with errors like this.

I ran Windows Memory Diagnostic and OCCT to test. They didn't report any problems.

I'm not sure from your answer, but were you able to reproduce the issue?
Also I'm skeptic about the random memory flip. How can that cause this error for 11 saves, spanning more than 1 hours?

I'm happy to help in ...

Exact same crash happens with the "full" version of the game, without steam

The game crashes when I try to load my last manual savegame (attached), and also my last 10 autosaves.
No mods installed, using vanilla, downloaded from steam.
The only modification I did was that I changed the number of autosave-slots to 10 in %APPDATA%/Factorio/config/config.ini.

My latest ...