I saved a game and when I later resumed it,
1) none of the rooms were being recognized ('No room' 'Enclose this space with walls and doors to make a room')
2) none of the electrical devices were recognized to be connected. ('No Power Consumers' 'No Wire Connected')
3) plumbing also had connection problems ('No Liquid Intake')
This despite nothing being otherwise wrong (the wires were all there and connected as per the power overlay, and the room contents/sizes were all correct)
Note that I am using Windows 8.1 and this was my first resumed game after the occupational upgrade (which I started from the same version)
Didn't have any ventilation runs going yet, so I don't know if those were affected.
Also note that repeated attempts at a resume didn't make any difference.
Everything else AFAIK looked and worked fine.