I built my fort on the mountaintop and dug deep into the excavations, with no sign of trouble. However, something weird has started happening. The game freezes completely, starts eating up all my RAM, and when it reaches its maximum, it drops most of it and starts eating it all over again. And so on, with no results. My game froze for half an hour and nothing happened.
(In the Discord bug discussion section, you can see how it ate 20 GB of RAM and it still isn't enough.)