My husband and i both have well-developed games, with large fully furnished and stocked shops. Neither of us have played our games for a couple of months (my save is dated May 29, his is somewhere close to that). Our saves were from version 7023.

Today, he updated to 7150. When he loaded his saved game from a couple months ago, the walls and floors were there, but everything else was gone, and his shop owner was reset to default.

So i tested mine. I first opened my saved game without updating, and it opened perfectly fine, everything was there. I then exited and did the update to 7150. When i opened the game again, the walls and floors were there, but everything else was gone, and my shop owner was reset to default. So, i exited and reverted back to version 7023, opened it again, and everything is fine again.

We both have Windows 10, using GOG Galaxy.