Mike Young

I'm also having this problem. Every time I open a single-player world to LAN in 1.8, when I go to save and quit, the game simply stops responding. I'm forced to forcibly close the program via the task manager. The launcher then reappears, and the last thing that appears in the console is "Saving chunks for level 'xxx'/The End"

So, to recap for reproduction, follow these steps:
1. Run Windows (may depend on version, architecture, and Java version)
2. Launch 1.8, load a single-player survival world, open to LAN.
3. Play around a bit (break blocks, explore, issue commands maybe?)
4. Attempt to save and quit, which should cause Minecraft to stop responding.

I'm running Windows 7 64-bit, with 64-bit Java 8. I've attached the console output log, even though it isn't an actual crash report.

Still occurs in 14w34b.

Can confirm, this is still showing up in 14w32a. Loaded 1.7.10 survival world in newest (14w32a) snapshot and output console shows numerous 'Invalid Statistic' warnings.

I've also seen this issue pop up in 13w05a/b. Setting the option for Smooth Lighting to off seems to alleviate the frame rate issues.