Alt tab while in the game, even in the menu itself prior joining a server.
Be in the game itself or in a server already alive.
Alt tab for 5 minutes, return to the game from unfocused alt tab just by clicking on it as you would normally by returning the focus to it
black screen frozen, requiring ctrl alt delete crash
Afterwards, you might quite often experience a struggle to launch the game for the first 2 times, or once. After such alt tab related freeze.
You just start the game again, and as it starts with it loading, and blackscreen, same crash.
Just rinse and repeat once or twice then it will be all normal.