I was paying on 1.19 pre-release 1, I was just exploring the deep dark on a creative world. I then closed the world, since I had put the render distance too far up. It took too long to save the world, which ended up in the world using too much ram. So I picked the option to go back to main title menu, then this happened:

Here is a link to the video if the file won't work, just in case:
https://streamable.com/fxt243