Hi ! This is a strange issue. Are you starting the game from Steam ? Helium Rain uses Steam Cloud, if you let that enabled, it's a possible way to lose progress (by playing offline, then with Steam).

Yes, I always start the game from Steam. I'm not sure whether I'm using Steam Cloud or not, but whatever the default setting is on that, I haven't ever changed it.

As an aside, one possible explanation is that sometimes the game freezes for me and I have to kill it (a separate issue, of course).

In both instances, save #2 was the one I was most recently playing, so it is possible that I killed the game in the course of saving, which somehow corrupted the save in the process of autosave resulting in its deletion (although I always waited at least 30s post-freeze to kill so as to try to avoid this kind of thing).

I don't remember for sure if I killed the game immediately prior to the patch.

Really strange. Can you look inside ~/.config/Epic/HeliumRain/Saved/SaveGames and see if a SaveSlotX.json is present for the missing save ?

Could you try with the cloud save off in Steam's settings, and see if you still have the issue ? I don't think we've ever saw something like that happen. If you want to back the saves up, copy the files from the directory above.

Doh! I started a new game in the save slot, so yes of course there is a file there, but it is for my new game I just started in the same slot, and I doubt there is any way of knowing whether there was before I did so.

For now, then, perhaps I'll inotifywait backup the saves and update if it happens again. And yes, I'll disable cloud save.

If there is some way to enable logging, I could start taking logs also so that I have them to provide if it goes awry again.