I've just suffered my fourth case of the game just suddenly terminating in the last 24 hours:
- Mishemlam, exiting (cannot guarantee that it didn't happen just before reching the exit, though) an attraction section twice (not sure if it was the same one or not).
- Mishelam, when gaining back control after going downstairs for night search for KeA.
- Chapter 3 day 1, exiting Downtown district after doing a daily tour of the district.

Each of the three first cases has resulted in an integrity check and/or download when the game is attempted to be started again. The first time failed to actually start anything until after rebooting, so I've rebooted after the other two crashes as well.
I expect things will go the same way this fourth time...

Edit:
It appears these issues were caused by virus detection and eliminatin, as my anti virus software decided the game was infected by PDM Trojan Win32 Generic. I don't know if this is a real or false detection, though.