Crash upon loading 14w30c

I have no idea what happened. Immediate crash upon loading world. I wish I had a hug 😞

---- Minecraft Crash Report ----
// I'm sorry, Dave.

Time: 7/27/14 7:41 PM
Description: Unexpected error

java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
	at java.util.HashMap$ValueIterator.next(Unknown Source)
	at cly.a(SourceFile:129)
	at cly.a(SourceFile:76)
	at ciy.a(SourceFile:510)
	at cht.a(SourceFile:1211)
	at cht.a(SourceFile:1117)
	at cht.b(SourceFile:970)
	at brp.ar(SourceFile:896)
	at brp.a(SourceFile:311)
	at net.minecraft.client.main.Main.main(SourceFile:120)


A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Stacktrace:
	at java.util.HashMap$HashIterator.nextEntry(Unknown Source)
	at java.util.HashMap$ValueIterator.next(Unknown Source)
	at cly.a(SourceFile:129)
	at cly.a(SourceFile:76)
	at ciy.a(SourceFile:510)
	at cht.a(SourceFile:1211)
	at cht.a(SourceFile:1117)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [cha['Johns_World3'/488, l='MpServer', x=2.40, y=63.00, z=111.25]]
	Chunk stats: MultiplayerChunkCache: 70, 70
	Level seed: 0
	Level generator: ID 03 - amplified, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: -60.00,64.00,248.00 - World: (-60,64,248), Chunk: (at 4,4,8 in -4,15; contains blocks -64,0,240 to -49,255,255), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 37980160 game time, 42006268 day time
	Level dimension: 0
	Level storage version: 0x00000 - Unknown?
	Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
	Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
	
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at ccz.a(SourceFile:308)
	at brp.b(SourceFile:2254)
	at brp.a(SourceFile:325)
	at net.minecraft.client.main.Main.main(SourceFile:120)

-- System Details --
Details:
	Minecraft Version: 14w30c
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_65, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 337268024 bytes (321 MB) / 816316416 bytes (778 MB) up to 1908932608 bytes (1820 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx2G
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Launched Version: 14w30c
	LWJGL: 2.9.1
	OpenGL: GeForce GT 545/PCIe/SSE2 GL version 4.4.0, NVIDIA Corporation
	GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.
VBOs are available because OpenGL 1.5 is supported.

	Using VBOs: No
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Packs: []
	Current Language: English (US)
	Profiler Position: N/A (disabled)

(Had to delete some things due to word limit hope it wasn't anything important)