When opening a singleplayer world to LAN, the game works just fine until the host opts to close the world by pressing "Save and Quit to Title".

Upon doing so, the game becomes unresponsive. The only way to close it is to make windows realize that it is unresponsive, and force close.

The launcher opens as usual afterwards, but has no indication that the game has crashed, it operates as if the game had been shut down normally.

As a side note, the LAN world had cheats enabled, and there were no other players on the server.