[1.1.33] Corrupted Save & All 3 Auto Saves (only for this specific map - other saves load)

[Runningfrenzy]

1.) What did I do?
--Saved the game as per normal, was playing on 22 May, 2021 without issue all day, utilizing auto-saves as normal. Completed for the day and manually saved, exit the game, and quit the game without issue. Started Factorio and went to load the game to play again on 23 May and none of the 4 files will load (manual save or 3 auto-saves).
--No mods at all are installed, nor have ever been installed.
2.) What happened?
--Throws "Corrupt map: unknown tile 128" when trying to load the manual save
--Throws "Corrupt map: unknown tile 0" other times if reload attempted numerous times
--Other previous game files still load. Issue only appears to be for this specific map.
3.) What did I expect to happen instead?
--Expected map to load and return to previous state at time of last save.

Manual Save -> https://drive.google.com/file/d/1dATYY3 ... sp=sharing
Autosave 1 -> https://drive.google.com/file/d/1yHVf6m ... sp=sharing
Autosave 2 -> https://drive.google.com/file/d/17OslAD ... sp=sharing
Autosave 3 -> https://drive.google.com/file/d/1X8YBNU ... sp=sharing

Mods directory only contains attached "mod-list.json" file (still attached for posterity to follow the report guidelines) =)

Thanks in advance for any help!

[posila]

I've taken a quick look and it is not easy to determine what was saved out incorrectly and what to change to fix it in your case ... I don't want you to lose your 500hr map, and I'll put more time into trying to recover the save, but I don't have much time to do so this week

[Runningfrenzy]

I truly appreciate your looking at it (whenever you can), and all you can do! Thanks in advance!!

[posila]

I finally got around taking deeper look into it and managed to repair the save ... one tile was saves with size 4, but it should have been size 2, so it seems like a random bit flip, probably due to cosmic ray or something.

https://www.dropbox.com/s/ar2x6eouzxjt2 ... d.zip?dl=0

[Runningfrenzy]

Thank you so much! =)
Have to love the phenomenon of computers and how they choose to save =)

I'll try to remember to save "versions" for each save going forward, or increase the number of auto saves and verify the saves going forward!