Hello.
I don't know what happens, US2 is crashing many times, at this rate, the achievement 10^4 will be reached sooner than I thought
I have just had the black screen bug, when I switch between windows, when I click again on US2, the screen went all black, but the menu buttons were still there, as I remembered their location, I was able to toggle between fullscreen and window screen. Then I tried to blindly click on another the invisible menu to the right, and US2 finally crashed.
It seems that after some time playing the simulation it begins to be unstable.
While I am writing this, I am experiencing the bug for the second time. (so twice in 15 min)