[MC-57033] Game crashes when new chunks are loaded

i loaded a new world and as soon as i spawned i noticed chunk loading was a bit glitchy. so then i played for a while longer and found a ice spike biome then the game came to a complete halt and crashed within seconds. so chunk loading appears to be bugged sorry if this is a bit much but i just copied the whole log file
[10:17:19] [Client thread/INFO]: Setting user: stuffjunk
[10:17:19] [Client thread/INFO]: (Session ID is token:007d8ac5490145ecaddfa02b3a79d2fe:29e94115874f48618f5cf6bc071181d7)
[10:17:19] [Client thread/INFO]: LWJGL Version: 2.9.1
[10:17:20] [Client thread/INFO]: Reloading ResourceManager: Default
[10:17:21] [Sound Library Loader/INFO]: Sound engine started
[10:17:22] [Client thread/INFO]: Created: 512x512 textures-atlas
[10:17:23] [MCO Availability Checker #1/ERROR]: Couldn't connect to Realms
cre: 
	at cqj.a(SourceFile:251) ~[14w25a.jar:?]
	at cqj.b(SourceFile:86) ~[14w25a.jar:?]
	at bpv.run(SourceFile:206) [14w25a.jar:?]
[10:17:29] [Server thread/INFO]: Starting integrated minecraft server version 14w25a
[10:17:29] [Server thread/INFO]: Generating keypair
[10:17:29] [Server thread/INFO]: Converting map!
[10:17:29] [Server thread/INFO]: Scanning folders...
[10:17:29] [Server thread/INFO]: Total conversion count is 0
[10:17:29] [Server thread/INFO]: Preparing start region for level 0
[10:17:30] [Server thread/INFO]: Preparing spawn area: 11%
[10:17:31] [Server thread/INFO]: Preparing spawn area: 27%
[10:17:32] [Server thread/INFO]: Preparing spawn area: 44%
[10:17:33] [Server thread/INFO]: Preparing spawn area: 61%
[10:17:34] [Server thread/INFO]: Preparing spawn area: 77%
[10:17:35] [Server thread/INFO]: Preparing spawn area: 98%
[10:17:35] [Server thread/INFO]: Changing view distance to 12, from 10
[10:17:35] [Server thread/INFO]: stuffjunk[local:E:4eabdc89] logged in with entity id 188 at (-178.5, 72.0, 254.5)
[10:17:35] [Server thread/INFO]: stuffjunk joined the game
[10:17:58] [Server thread/INFO]: Saving and pausing game...
[10:17:58] [Server thread/INFO]: Saving chunks for level 'New World'/Overworld
[10:17:58] [Server thread/INFO]: Saving chunks for level 'New World'/Nether
[10:17:58] [Server thread/INFO]: Saving chunks for level 'New World'/The End
[10:18:00] [Server thread/INFO]: stuffjunk has just earned the achievement [Taking Inventory]
[10:18:00] [Client thread/INFO]: [CHAT] stuffjunk has just earned the achievement [Taking Inventory]
[10:18:11] [Client thread/WARN]: Unable to play unknown soundEvent: minecraft:damage.thorns
[10:18:31] [Client thread/WARN]: Unable to play unknown soundEvent: minecraft:damage.thorns
[10:19:10] [Server thread/INFO]: [stuffjunk: Set own game mode to Survival Mode]
[10:19:10] [Client thread/INFO]: [CHAT] Your game mode has been updated
[10:19:32] [Client thread/WARN]: Unable to play unknown soundEvent: minecraft:damage.thorns
[10:19:35] [Server thread/INFO]: Saving and pausing game...
[10:19:35] [Server thread/INFO]: Saving chunks for level 'New World'/Overworld
[10:19:35] [Server thread/INFO]: Saving chunks for level 'New World'/Nether
[10:19:35] [Server thread/INFO]: Saving chunks for level 'New World'/The End
[10:19:39] [Server thread/INFO]: Changing difficulty to HARD, from NORMAL
[10:22:18] [Server thread/INFO]: Saving and pausing game...
[10:22:18] [Server thread/INFO]: Saving chunks for level 'New World'/Overworld
[10:22:18] [Server thread/INFO]: Saving chunks for level 'New World'/Nether
[10:22:18] [Server thread/INFO]: Saving chunks for level 'New World'/The End
[10:22:23] [Server thread/INFO]: Changing difficulty to PEACEFUL, from HARD
[10:22:30] [Server thread/INFO]: [stuffjunk: Set own game mode to Creative Mode]
[10:22:30] [Client thread/INFO]: [CHAT] Your game mode has been updated
[10:24:43] [Client thread/INFO]: Warning: Clientside chunk ticking took 186 ms
[10:24:44] [Client thread/INFO]: Warning: Clientside chunk ticking took 106 ms
[10:24:44] [Client thread/INFO]: Warning: Clientside chunk ticking took 107 ms
[10:24:45] [Client thread/INFO]: Warning: Clientside chunk ticking took 153 ms
[10:24:45] [Client thread/INFO]: Warning: Clientside chunk ticking took 156 ms
[10:24:45] [Client thread/INFO]: Warning: Clientside chunk ticking took 151 ms
[10:24:45] [Client thread/INFO]: Warning: Clientside chunk ticking took 151 ms
[10:24:45] [Client thread/INFO]: Warning: Clientside chunk ticking took 155 ms
[10:24:45] [Client thread/INFO]: Warning: Clientside chunk ticking took 153 ms
[10:24:46] [Client thread/INFO]: Warning: Clientside chunk ticking took 152 ms
[10:24:46] [Client thread/INFO]: Warning: Clientside chunk ticking took 155 ms
[10:24:46] [Client thread/INFO]: Warning: Clientside chunk ticking took 155 ms
[10:24:46] [Client thread/INFO]: Warning: Clientside chunk ticking took 152 ms
[10:24:46] [Client thread/INFO]: Warning: Clientside chunk ticking took 154 ms
[10:24:47] [Client thread/INFO]: Warning: Clientside chunk ticking took 154 ms
[10:24:47] [Client thread/INFO]: Warning: Clientside chunk ticking took 105 ms
[10:24:47] [Client thread/INFO]: Warning: Clientside chunk ticking took 154 ms
[10:24:47] [Client thread/INFO]: Warning: Clientside chunk ticking took 106 ms
[10:24:47] [Client thread/INFO]: Warning: Clientside chunk ticking took 154 ms
[10:24:47] [Client thread/INFO]: Warning: Clientside chunk ticking took 105 ms
[10:24:47] [Client thread/INFO]: Warning: Clientside chunk ticking took 154 ms
[10:24:48] [Client thread/INFO]: Warning: Clientside chunk ticking took 169 ms
[10:24:48] [Client thread/INFO]: Warning: Clientside chunk ticking took 146 ms
[10:26:08] [Client thread/WARN]: Something's taking too long! 'root' took aprox 111.645867 ms
[10:26:08] [Client thread/WARN]: Something's taking too long! 'root' took aprox 119.703022 ms
[10:26:10] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 113.368864 ms
[10:26:10] [Client thread/WARN]: Something's taking too long! 'root' took aprox 124.061226 ms
[10:26:13] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 147.996336 ms
[10:26:13] [Client thread/WARN]: Something's taking too long! 'root' took aprox 153.444244 ms
[10:26:13] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 114.72752 ms
[10:26:13] [Client thread/WARN]: Something's taking too long! 'root' took aprox 132.442575 ms
[10:26:14] [Client thread/WARN]: Something's taking too long! 'root.tick' took aprox 105.736422 ms
[10:26:14] [Client thread/WARN]: Something's taking too long! 'root' took aprox 119.041051 ms
[10:26:30] [Client thread/INFO]: Warning: Clientside chunk ticking took 105 ms
[10:26:30] [Client thread/INFO]: Warning: Clientside chunk ticking took 102 ms
[10:27:45] [Client thread/WARN]: Null returned as 'hitResult', this shouldn't happen!
[10:28:33] [Client thread/INFO]: Warning: Clientside chunk ticking took 349 ms
[10:28:33] [Client thread/INFO]: Warning: Clientside chunk ticking took 335 ms
[10:28:33] [Client thread/INFO]: Warning: Clientside chunk ticking took 310 ms
[10:28:34] [Client thread/INFO]: Warning: Clientside chunk ticking took 269 ms
[10:31:00] [Client thread/INFO]: Warning: Clientside chunk ticking took 131 ms
[10:32:01] [Server thread/INFO]: Saving and pausing game...
[10:32:01] [Server thread/INFO]: Saving chunks for level 'New World'/Overworld
[10:32:01] [Server thread/INFO]: Saving chunks for level 'New World'/Nether
[10:32:01] [Server thread/INFO]: Saving chunks for level 'New World'/The End
[10:32:08] [Server thread/INFO]: Changing difficulty to HARD, from PEACEFUL
[10:33:11] [Client thread/WARN]: Unable to play unknown soundEvent: minecraft:mob.witch.idle
[10:33:12] [Client thread/WARN]: Unable to play unknown soundEvent: minecraft:mob.witch.hurt
[10:33:14] [Client thread/WARN]: Unable to play unknown soundEvent: minecraft:mob.witch.hurt
[10:33:15] [Client thread/WARN]: Unable to play unknown soundEvent: minecraft:mob.witch.hurt
[10:33:25] [Client thread/INFO]: Warning: Clientside chunk ticking took 111 ms
[10:33:48] [Client thread/INFO]: [CHAT] Saved screenshot as 2014-06-18_10.33.47.png
[10:34:15] [Server thread/ERROR]: Encountered an unexpected exception
u: Exception ticking world
	at net.minecraft.server.MinecraftServer.w(SourceFile:574) ~[14w25a.jar:?]
	at net.minecraft.server.MinecraftServer.v(SourceFile:506) ~[14w25a.jar:?]
	at cof.v(SourceFile:132) ~[14w25a.jar:?]
	at net.minecraft.server.MinecraftServer.run(SourceFile:422) [14w25a.jar:?]
	at java.lang.Thread.run(Unknown Source) [?:1.7.0_11]
Caused by: java.lang.RuntimeException: Already decorating
	at amt.a(SourceFile:25) ~[14w25a.jar:?]
	at amm.a(SourceFile:397) ~[14w25a.jar:?]
	at anc.a(SourceFile:40) ~[14w25a.jar:?]
	at bab.a(SourceFile:482) ~[14w25a.jar:?]
	at ot.a(SourceFile:175) ~[14w25a.jar:?]
	at ayt.a(SourceFile:997) ~[14w25a.jar:?]
	at ot.c(SourceFile:104) ~[14w25a.jar:?]
	at ot.d(SourceFile:117) ~[14w25a.jar:?]
	at alu.b(SourceFile:290) ~[14w25a.jar:?]
	at ou.h(SourceFile:288) ~[14w25a.jar:?]
	at ou.c(SourceFile:179) ~[14w25a.jar:?]
	at net.minecraft.server.MinecraftServer.w(SourceFile:570) ~[14w25a.jar:?]
	... 4 more
[10:34:15] [Server thread/ERROR]: This crash report has been saved to: C:\Users\Default.Default-PC\AppData\Roaming\.minecraft\crash-reports\crash-2014-06-18_10.34.15-server.txt
[10:34:16] [Server thread/INFO]: Stopping server
[10:34:16] [Server thread/INFO]: Saving players
[10:34:16] [Client Shutdown Thread/INFO]: Stopping server
[10:34:16] [Client Shutdown Thread/INFO]: Saving players
[10:34:16] [Client Shutdown Thread/WARN]: Failed to save player data for stuffjunk
[10:34:16] [Client Shutdown Thread/INFO]: Saving worlds
[10:34:16] [Client Shutdown Thread/INFO]: Saving chunks for level 'New World'/Overworld
[10:34:16] [Server thread/INFO]: Saving worlds
[10:34:16] [Server thread/INFO]: Saving chunks for level 'New World'/Overworld