I may be wrong, but after a bit more investigation, my impression is that this has to do with the "shifting dungeons" room - as if the game doesn't save it properly?

I do have a set of shifting room save files that all work.

The save file provided looks corrupted in some way but I yet have no idea what exact type of corruption that might be. Did anything else happen before you saved this?

The message you see about an expected chunk not being found can only occur when you are trying to load a game. Is this game a game you saved on a shifting dungeon level? Or is it a backup from some other crash?

added another savefile going with the JSON crash trying to load D:3 from D:2 (a shifting dungeon level)

is it supposed to be like a rockslide?

I tested the boundaries and it looped me to the top through it, if that has anything to do with it

This happened when one of my chars was descending a dungeon level in the Unremarkable Dungeon. Can't remember which level... the game crashes again immediately when you try and reload it from backup, anyway.
I've attached the .bak and .err files generated.
This was on Windows 10.

All the games it's happened on were normal except for the crash. The message does indeed pop up in-game - causing a crash - and then again when trying to load the resultant save file.

Also - in one game (not the attached save) I saved and quit normally on a shifting dungeons level (no crash), then loaded the same file immediately, and it gave the same error.

Just happened to me, decending to UD: 6. I got the 'you sense the forces of the nether approaching' message, followed by [saving backup copy rolf.bak. please stand by.] and the expected chunk JSON message. Reloading causes an instant crash.

Quite sad. Had a fun character just get the crash after being in a shifting level. Seems like the game is having trouble saving shifting levels?

This is the reason it might be a good idea to keep not one, but two last save games, in case something breaks in the saving process.

That's a good idea! You should submit an rfe for that, it would greatly smooth out the prerelease phase.

I just had this happen. Had been in a shifting room area maybe 100 turns earlier. Save won't load at all.

ditto. Had a bard with perfect skill rolls too :(

so uh i like the R65 version this going to get fixed? :)

It looks like this is still an issue, as of the newest version of the game (r65). I've had several saves corrupt already due to this, usually from autosaves when switching floors from a floor with a shifting room.

Is it being worked on at all?

r65 is the first release where this was a problem and there hasn't been any newer versions since so it makes sense that this would be a problem in your games on that version. I'm pretty sure The Creator is still working on this and several other bugs that were introduced in r65.

Ah, gotcha. I was under the impression this was reported during r64, due to the way some of the above comments were worded.

Yeah, it does kind of seem that way but if you look at the bug report description to the right it says it was reported in r65, just a tip for the future. I'm hoping this does get fixed soonish because r65 brings in some cool interesting stuff.

I have rewritten some part of the internal code that might be responsible for it without seeing any actual problem. But sometimes rewriting helps. Though currently we still are confused.

I have removed the sources for inconsistencies. Now things should be stable.