1. 8. 0 Any ruins generated using the SpaceMaster "Random Ruin" button disappear when the game is loaded back up.
All naturally generated ruins and any anomalies generated by "Random Ruin" button remain.
Pressing the ruin button when a ruin already exists will delete the existing ruin. I've removed this behaviour as I suspect this was causing issues. Instead, you get a pop up explaining the ruin already exists.
I just tested:
Create new game in fresh database (all default settings)
SM On
SM GeoSurvey full system
Select Mars (which had no ruin) and hit random ruin. It generated a abandoned colony and an installation (Bio 100%)
Closed system window. Saved game. Exit.
Relaunch and check, the installation is still there, the ruin is gone.
I repeated again with another new game in a fresh database. Added ruins to mars, Venus, and mercury (none of which had one to start). Venus also got an installation. Saved, exit, reload. All the ruins are gone. The installation on Venus is still there.
Based on this, I don't think the bug is not only when hitting random ruin on a planet that already has a ruin.
Additionally, being able to re-roll ruins is a nice feature when setting up a game where you want something like a sizable ruin on mars to act as a jump-start to a conventional start, though that's obviously just a nice to have.