I was in the process of expanding some rail lines but had not yet connected them to the network nor put any trains on them. The autosave dialog box appeared and immediately I heard the crash tones. The error was "unspecified".

The save is too big to attach but you can find it here: https://www ...

I've never crashed Factorio before, but crashed with this error twice now over the last 2 days. The first time, I placed a train with a blueprint, and it crashed a minute later. The second time, I did nothing - in fact, I was watching TV while the game ran. It crashed after about 10 minutes of no ...