Game freezes when "Save and Quit to Title" is pressed.

When I am playing on my survival world, If I press the Save and Quit to Title button, the game freezes, I can't force quit (apple Q) the game, but it seems to save my progress and then freeze. I play on fullscreen, and have a Late 2009 iMac, if either of those details help at all. A copy of my world is attached, if that helps at all.

What I expected to happen was...:
The game would quit normally, save, and not freeze.

What actually happened was...:
The game saved, and froze up completely. (I can still move my mouse when it's frozen.)

Steps to Reproduce:
1. Play a world.
2. Press Escape.
3. Click "Save and Quit to Title"
4. Congrats! The game is now frozen!