Hopper: java.lang.NullPointerException

java.lang.NullPointerException
	at bjr.a(SourceFile:44)
	at bjr.a(SourceFile:16)

---- Minecraft Crash Report ----
// Oh - I know what I did wrong!

Time: 9/19/13 3:04 PM
Description: Rendering entity in world

java.lang.NullPointerException
	at bjr.a(SourceFile:44)
	at bjr.a(SourceFile:16)
	at bjo.a(SourceFile:215)
	at bjo.a(SourceFile:196)
	at bmr.a(SourceFile:32)
	at bmr.a(SourceFile:17)
	at bmr.a(SourceFile:12)
	at bmw.a(SourceFile:106)
	at bmw.a(SourceFile:98)
	at bin.a(SourceFile:354)
	at big.a(SourceFile:966)
	at big.b(SourceFile:798)
	at awo.aa(SourceFile:758)
	at awo.e(SourceFile:681)
	at net.minecraft.client.main.Main.main(SourceFile:104)


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

-- Head --
Stacktrace:
	at bjr.a(SourceFile:44)
	at bjr.a(SourceFile:16)

-- Entity being rendered --
Details:
	Entity Type: FallingSand (tr)
	Entity ID: 160215
	Entity Name: Falling Block
	Entity's Exact location: 3.75, 0.03, -31.25
	Entity's Block location: World: (3,0,-32), Chunk: (at 3,0,0 in 0,-2; contains blocks 0,0,-32 to 15,255,-17), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,0,-512 to 511,255,-1)
	Entity's Momentum: 0.00, 0.00, 0.00
	Immitating block ID: 0
	Immitating block data: 0

-- Renderer details --
Details:
	Assigned renderer: bjr@45e20e8a
	Location: 0.00,0.00,0.00 - World: (0,0,0), Chunk: (at 0,0,0 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Rotation: 0.0
	Delta: 0.8222814
Stacktrace:
	at bjo.a(SourceFile:215)
	at bjo.a(SourceFile:196)
	at bmr.a(SourceFile:32)
	at bmr.a(SourceFile:17)
	at bmr.a(SourceFile:12)

-- Tile Entity Details --
Details:
	Name: MobSpawner // avc
	Block type: ID #52 (tile.mobSpawner // arz)
	Block data value: 0 / 0x0 / 0b0000
	Block location: World: (-99,47,-52), Chunk: (at 13,2,12 in -7,-4; contains blocks -112,0,-64 to -97,255,-49), Region: (-1,-1; contains chunks -32,-32 to -1,-1, blocks -512,0,-512 to -1,255,-1)
	Actual block type: ID #52 (tile.mobSpawner // arz)
	Actual block data value: 0 / 0x0 / 0b0000
Stacktrace:
	at bmw.a(SourceFile:106)
	at bmw.a(SourceFile:98)
	at bin.a(SourceFile:354)
	at big.a(SourceFile:966)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bgf['deleonwill920'/133428, l='MpServer', x=-102.75, y=46.90, z=-20.70]]
	Chunk stats: MultiplayerChunkCache: 302, 302
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (-94,50,-3), Chunk: (at 2,3,13 in -6,-1; contains blocks -96,0,-16 to -81,255,-1), Region: (-1,-1; contains chunks -32,-32 to -1,-1, blocks -512,0,-512 to -1,255,-1)
	Level time: 1074635 game time, 1414 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: 36 total; [pj['Painting'/140161, l='MpServer', x=399.50, y=69.00, z=384.94], pj['Painting'/142909, l='MpServer', x=392.06, y=78.00, z=410.50], pj['Painting'/133461, l='MpServer', x=424.06, y=68.00, z=409.00], pj['Painting'/133456, l='MpServer', x=419.50, y=69.00, z=384.94], pj['Painting'/142916, l='MpServer', x=424.06, y=68.00, z=409.00], pj['Painting'/142906, l='MpServer', x=384.94, y=78.00, z=410.50], pj['Painting'/142907, l='MpServer', x=388.50, y=78.00, z=406.94], bgf['deleonwill920'/133428, l='MpServer', x=-102.75, y=46.90, z=-20.70], pj['Painting'/142908, l='MpServer', x=388.50, y=78.00, z=414.06], pj['Painting'/142915, l='MpServer', x=419.50, y=69.00, z=384.94], ts['item.tile.glass'/160246, l='MpServer', x=-103.42, y=29.89, z=-32.19], pj['Painting'/133436, l='MpServer', x=384.94, y=78.00, z=410.50], pj['Painting'/133438, l='MpServer', x=388.50, y=78.00, z=414.06], pj['Painting'/133437, l='MpServer', x=388.50, y=78.00, z=406.94], pj['Painting'/133439, l='MpServer', x=392.06, y=78.00, z=410.50], pj['Painting'/133472, l='MpServer', x=434.94, y=68.00, z=416.00], pj['Painting'/133470, l='MpServer', x=434.94, y=68.00, z=413.00], pj['Painting'/133448, l='MpServer', x=415.50, y=69.00, z=384.94], pj['Painting'/133447, l='MpServer', x=403.50, y=69.00, z=384.94], pj['Painting'/133446, l='MpServer', x=407.50, y=69.00, z=384.94], pj['Painting'/142913, l='MpServer', x=434.94, y=68.00, z=410.00], pj['Painting'/133445, l='MpServer', x=411.50, y=69.00, z=384.94], pj['Painting'/142912, l='MpServer', x=434.94, y=68.00, z=413.00], pj['Painting'/142900, l='MpServer', x=434.94, y=68.00, z=416.00], pj['Painting'/133435, l='MpServer', x=399.50, y=69.00, z=384.94], pj['Painting'/142911, l='MpServer', x=434.94, y=68.00, z=407.00], pj['Painting'/133451, l='MpServer', x=407.50, y=67.00, z=420.94], pj['Painting'/133452, l='MpServer', x=411.50, y=67.00, z=420.94], pj['Painting'/142905, l='MpServer', x=415.50, y=69.00, z=384.94], pj['Painting'/142904, l='MpServer', x=403.50, y=69.00, z=384.94], pj['Painting'/142903, l='MpServer', x=407.50, y=69.00, z=384.94], pj['Painting'/142902, l='MpServer', x=411.50, y=69.00, z=384.94], pj['Painting'/142917, l='MpServer', x=407.50, y=67.00, z=420.94], pj['Painting'/142918, l='MpServer', x=411.50, y=67.00, z=420.94], pj['Painting'/133469, l='MpServer', x=434.94, y=68.00, z=407.00], pj['Painting'/133471, l='MpServer', x=434.94, y=68.00, z=410.00]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at bga.a(SourceFile:294)
	at awo.b(SourceFile:1872)
	at awo.e(SourceFile:690)
	at net.minecraft.client.main.Main.main(SourceFile:104)

-- System Details --
Details:
	Minecraft Version: 13w38a
	Operating System: Windows 8 (amd64) version 6.2
	Java Version: 1.7.0_10, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 182464768 bytes (174 MB) / 954466304 bytes (910 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 7273 (407288 bytes; 0 MB) allocated, 2 (112 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 13w38a
	LWJGL: 2.9.0
	OpenGL: GeForce 210/PCIe/SSE2 GL version 3.3.0, NVIDIA Corporation
	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)
	Vec3 Pool Size: 280 (15680 bytes; 0 MB) allocated, 280 (15680 bytes; 0 MB) used