I notice the log has

libraries/SDL2/src/audio/coreaudio/SDL_coreaudio.m (675): default_device_changed

when opening the laptop, i was plugged into an external monitor via an "all in one" usb cable which includes a hub connection to a usb connect soundbar. This is my typical setup, but it's ...

1. What did you do?
Started steam and opened factorio at office (online). When on bus (offline) selected and loaded save, and played for a bit. When my stop came up, saved game and closed laptop. When i got home (online), after a bit, opened laptop to keep playing, and got the crash dialog to report ...

Looking at this again, maybe i'm confusing wires from the substation with the circuit wires, and everything is fine.

[Ignore this - i've rechecked it and deleted things to check, and I'm sure i just misinterpreted what was linked to what looking at the image].

I've got a small circuit, and when i copy/paste it as a blueprint, the copy has the wires incorrect compared to what was copied.
In the screen shot, i Cmd ...