I was playing in singleplayer and several things happen in a row:

1. lava is generated in an ice peak.
2. In spite of not having the server open in LAN, the server "closes".
3. Automatically the game closes and (although it is not seen in the clip) code 0 appears in the launcher.

-Update: the world was saved a little further back from where it was, but when returning to the site something similar has happened, but instead of closing the game, the minecraft application has remained completely black.