We discovered this on stream. We tried saving once, but it didn't work, so we switched to the classic version of the game. Here's a video of it happening (02:32:26):
I'm not sure what I'm looking at, just looks like it's being reset and other versions run... I don't see any corruption or anything, just goes back to the menu.
You can't save using the Next snapshot, but there's saving built in. 4 slots available.
I can't see anyone selecting "Save" because no save messages come up.