I don't get what happened, i was in my test world flying around and it crashed, for two times

---- Minecraft Crash Report ----
// You should try our sister game, Minceraft!

Time: 06/02/14 15.37
Description: Tesselating block in world

java.lang.NullPointerException: Tesselating block in world
	at bsv.a(SourceFile:80)
	at bsv.b(SourceFile:42)
	at bro.a(SourceFile:220)
	at brn.b(SourceFile:274)
	at bqm.a(SourceFile:162)
	at bqy.a(SourceFile:1418)
	at bqr.a(SourceFile:1097)
	at bqr.b(SourceFile:935)
	at bdf.ag(SourceFile:805)
	at bdf.f(SourceFile:732)
	at net.minecraft.client.main.Main.main(SourceFile:154)


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

-- Head --
Stacktrace:
	at bsv.a(SourceFile:80)
	at bsv.b(SourceFile:42)
	at bro.a(SourceFile:220)

-- Block being tesselated --
Details:
	Block type: ID #50 (tile.torch // aqf)
	Block data value: 15 / 0xF / 0b1111
	Block location: World: (-282,59,90), Chunk: (at 6,3,10 in -18,5; contains blocks -288,0,80 to -273,255,95), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
Stacktrace:
	at brn.b(SourceFile:274)
	at bqm.a(SourceFile:162)
	at bqy.a(SourceFile:1418)
	at bqr.a(SourceFile:1097)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bqh['TheGriefersBay'/163, l='MpServer', x=-60,67, y=56,00, z=-7,53]]
	Chunk stats: MultiplayerChunkCache: 1089, 1089
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: -28,00,4,00,186,00 - World: (-28,4,186), Chunk: (at 4,0,10 in -2,11; contains blocks -32,0,176 to -17,255,191), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 2409695 game time, 1487 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: creative (ID 1). Hardcore: false. Cheats: false
	Forced entities: 6 total; [zz['Villager'/239, l='MpServer', x=-43,50, y=59,00, z=-36,50], xu['item.item.egg'/238, l='MpServer', x=-71,72, y=56,00, z=-19,13], wp['Chicken'/237, l='MpServer', x=-62,63, y=56,00, z=-7,63], bqh['TheGriefersBay'/163, l='MpServer', x=-60,67, y=56,00, z=-7,53], ye['entity.MinecartRideable.name'/35816, l='MpServer', x=-36,63, y=62,44, z=-38,27], ww['Cat'/240, l='MpServer', x=-42,59, y=59,50, z=-36,72]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at boe.a(SourceFile:308)
	at bdf.b(SourceFile:2017)
	at bdf.f(SourceFile:741)
	at net.minecraft.client.main.Main.main(SourceFile:154)

-- System Details --
Details:
	Minecraft Version: 14w06a
	Operating System: Windows 8 (amd64) version 6.2
	Java Version: 1.7.0_51, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 549663392 bytes (524 MB) / 1119879168 bytes (1068 MB) up to 6681001984 bytes (6371 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx7G
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 14w06a
	LWJGL: 2.9.1
	OpenGL: GeForce GTX 560/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.
Anisotropic filtering is supported and maximum anisotropy is 16.
Shaders are available because OpenGL 2.1 is supported.

	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)
	Anisotropic Filtering: On (16)