Upon saving and quitting a 1.8.1 Minecraft world, it freezes, and stops responding.

This is what it says in the log file:
[12:30:18] [Server thread/INFO]: kinky_boots lost connection: TextComponent{text='Disconnected', siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null, insertion=null}}
[12:30:18] [Server thread/INFO]: kinky_boots left the game
[12:30:18] [Server thread/INFO]: Stopping singleplayer server as player logged out
[12:30:18] [Server thread/INFO]: Stopping server
[12:30:18] [Server thread/INFO]: Saving players
[12:30:18] [Server thread/INFO]: Saving worlds
[12:30:18] [Server thread/INFO]: Saving chunks for level 'Minevolution'/Overworld
[12:30:18] [Server thread/INFO]: Saving chunks for level 'Minevolution'/Nether
[12:30:18] [Server thread/INFO]: Saving chunks for level 'Minevolution'/The End

But In The Game Output it says:

12:30:18] [Server thread/INFO]: kinky_boots lost connection: TextComponent{text='Disconnected', siblings=[], style=Style{hasParent=false, color=null, bold=null, italic=null, underlined=null, obfuscated=null, clickEvent=null, hoverEvent=null, insertion=null}}
[12:30:18] [Server thread/INFO]: kinky_boots left the game
[12:30:18] [Server thread/INFO]: Stopping singleplayer server as player logged out
[12:30:18] [Server thread/INFO]: Stopping server
[12:30:18] [Server thread/INFO]: Saving players
[12:30:18] [Server thread/INFO]: Saving worlds
[12:30:18] [Server thread/INFO]: Saving chunks for level 'Minevolution'/Overworld
u: Saving entity NBT
at wx.e(SourceFile:1193)
at wx.d(SourceFile:1151)
at bfw.a(SourceFile:243)
at bfw.a(SourceFile:114)
at qt.b(SourceFile:160)
at qt.a(SourceFile:204)
at qu.a(SourceFile:766)
at net.minecraft.server.MinecraftServer.a(SourceFile:361)
at net.minecraft.server.MinecraftServer.s(SourceFile:384)
at cyk.s(SourceFile:313)
at net.minecraft.server.MinecraftServer.run(SourceFile:481)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
at apz.k(SourceFile:129)
at aqa.a(SourceFile:134)
at agn.b(SourceFile:228)
at wx.e(SourceFile:1181)
... 11 more
u: Saving entity NBT
at wx.e(SourceFile:1193)
at wx.d(SourceFile:1151)
at bfw.a(SourceFile:243)
at bfw.a(SourceFile:114)
at qt.b(SourceFile:160)
at qt.a(SourceFile:204)
at qu.a(SourceFile:766)
at net.minecraft.server.MinecraftServer.a(SourceFile:361)
at net.minecraft.server.MinecraftServer.s(SourceFile:384)
at cyk.s(SourceFile:313)
at net.minecraft.server.MinecraftServer.run(SourceFile:481)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
at apz.k(SourceFile:129)
at aqa.a(SourceFile:134)
at agn.b(SourceFile:228)
at wx.e(SourceFile:1181)
... 11 more
[12:30:18] [Server thread/INFO]: Saving chunks for level 'Minevolution'/Nether
[12:30:18] [Server thread/INFO]: Saving chunks for level 'Minevolution'/The End

Upon force closing, it says in the Launcher Log:

[12:45:31 ERROR]: Game ended with bad state (exit code -805306369)
[12:45:31 INFO]: Ignoring visibility rule and showing launcher due to a game crash

//**Attached is the world with the latest.log file from the whole day till' it crashed when this happened.
**