I have been able to reproduce this multiple times...
Open Minecraft, launch "latest version" (default) – it just says 1.8?
Select Single Player, and a map
Open To LAN (I selected Survival, No Cheats, and the initial map was Creative/Cheats, but I don't think that matters)
After some period of time, various people joining, etc, try "Save and Quit to Title"
It just hangs. If it is full screen it is impossible to exit without logging in remotely (via SSH) and killing the PID.
~tommy
Dupe of MC-71357