Factorio Forums

Hi, one of my nuclear power plants suddenly stopped producing power, and I could see that all the components in the same heatpipe network were rapidly dropping in temperature, with almost half a million degrees below zero in the coldest places.

Investigating the problem a bit further I found one of the reactors having the rather intriguing temperature negative i (see screenshot). Removing that reactor I could see the other components starting to gain temperature again. (In the end I removed the entire heatpipe network and all attached machines to get rid of the ridiculous temperatures, and after that the game appears to work fine again.)

The issue is perfectly reproducible from the save, and I see no other stability issues. I've placed the character right next to the bugged reactor. It's an old save with lots of hours in it; I've played it since at least 0.16, possibly earlier. Plain vanilla, no mods. I've tried to attach it, but it doesn't appear to be working (it's 111.5 MB and I get an "Error parsing server response" exclamation mark from phpBB). Happy to provide it by some other means.

I've no idea what the cause may be - I was doing something completely unrelated and the reactor setup hasn't been touched for at least a hundred hours at this point. The three other nuclear plants continued to work fine.

I found one similar issue from last year about negative temperatures in heatpipes, but there the save was corrupted, which isn't the case here.

Upload the save to googledrive and post a public link, see 3638. If you can recreate the issue from a save that is not broken yet post that as well please and the steps to create the issue.

Thanks for the quick response. The save is available here.

I've also uploaded the last save I have before it happened here, but it's some 2-2.5 hours earlier.

According to the instructions I've attached a log as well. It's not the log from when it happened, just one from when I opened the buggy save later.

Unfortunately I don't have a repro - as said earlier I was doing something completely unrelated (shelling biters in another part of the map). Suddenly I noticed that I had a power problem and it took some time before I got to investigate the cause, so I guess the first save above is half an hour to an hour after the issue actually occurred.

Just to check, I loaded the save from before it happened and let it run past the time in the other save, and it didn't occur again (but of course I didn't even try to redo the same things I did the first time).

So it doesn't look easy to reproduce, but if I get it again I'll take more care to save the log and the autosaves.

Thanks for the report. Based off the inability to reproduce this from a working state and the extreme rarity of this happening in the many years the game has been out I highly suspect a random bit flip or single-event-upset on your system that corrupted the temperature in memory.

Unless you find a way to reproduce it from a working state there's nothing else we can do.

Yes, that's fair enough. It didn't cause any lasting effects either, once I rebuilt the heatpipe network.

I'm a bit curious how the temperature can take on a value that gets written out as "-i". You're not using a complex number data type for that, right? Maybe it's "-inf" that gets truncated somehow.

It's a simple 'double'.