Open any single player world to LAN, soon after save and quit. Pressing the save and quit button will freeze Minecraft indefinitely. Forcing the program to close will bring no crash report, and the world will have saved with no issue. This will occur no matter how long you have LAN open, ranging from open only a few seconds, to a few hours or more.

I host LAN all the time and this has only started up again with the recent 1.10 release of Minecraft.

EDIT: Potential version corruption? I no longer seem able to replicate this after deleting 1.10 and reinstalling it.