Hopper: java.lang.ClassCastException: cf cannot be cast to bx

java.lang.ClassCastException: cf cannot be cast to bx
	at by.c(SourceFile:111)
	at nj.b(SourceFile:151)
	at yp.g(SourceFile:61)
	at yp.e(SourceFile:268)
	at ye.v(SourceFile:505)
	at bgw.a(SourceFile:201)
	at bgw.a(SourceFile:109)
	at bgw.a(SourceFile:24)
	at bgl.a(SourceFile:204)
	at bgv.c(SourceFile:173)
	at bgv.a(SourceFile:44)
	at bgv.a(SourceFile:20)
	at bgl.a(SourceFile:204)
	at bgl.a(SourceFile:184)
	at bfl.a(SourceFile:326)
	at bfe.a(SourceFile:845)
	at bfe.b(SourceFile:695)
	at atv.S(SourceFile:686)
	at atv.d(SourceFile:619)
	at net.minecraft.client.main.Main.main(SourceFile:101)

---- Minecraft Crash Report ----
// I bet Cylons wouldn't have this problem.

Time: 19.09.13 18:47
Description: Reading NBT data

java.lang.ClassCastException: cf cannot be cast to bx
	at by.c(SourceFile:111)
	at nj.b(SourceFile:151)
	at yp.g(SourceFile:61)
	at yp.e(SourceFile:268)
	at ye.v(SourceFile:505)
	at bgw.a(SourceFile:201)
	at bgw.a(SourceFile:109)
	at bgw.a(SourceFile:24)
	at bgl.a(SourceFile:204)
	at bgv.c(SourceFile:173)
	at bgv.a(SourceFile:44)
	at bgv.a(SourceFile:20)
	at bgl.a(SourceFile:204)
	at bgl.a(SourceFile:184)
	at bfl.a(SourceFile:326)
	at bfe.a(SourceFile:845)
	at bfe.b(SourceFile:695)
	at atv.S(SourceFile:686)
	at atv.d(SourceFile:619)
	at net.minecraft.client.main.Main.main(SourceFile:101)


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

-- Corrupt NBT tag --
Details:
	Tag type found: INT
	Tag type expected: BYTE
	Tag name: Id
Stacktrace:
	at by.c(SourceFile:111)
	at nj.b(SourceFile:151)
	at yp.g(SourceFile:61)
	at yp.e(SourceFile:268)
	at ye.v(SourceFile:505)
	at bgw.a(SourceFile:201)
	at bgw.a(SourceFile:109)
	at bgw.a(SourceFile:24)

-- Entity being rendered --
Details:
	Entity Type: Item (ss)
	Entity ID: 115
	Entity Name: item.item.potion
	Entity's Exact location: 0,00, 0,00, 0,00
	Entity's Block location: 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)
	Entity's Momentum: 0,00, 0,20, -0,00

-- Renderer details --
Details:
	Assigned renderer: bgw@924c71f
	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: 0.0
Stacktrace:
	at bgl.a(SourceFile:204)
	at bgv.c(SourceFile:173)
	at bgv.a(SourceFile:44)
	at bgv.a(SourceFile:20)

-- Entity being rendered --
Details:
	Entity Type: ItemFrame (od)
	Entity ID: 42
	Entity Name: entity.ItemFrame.name
	Entity's Exact location: 605,50, 5,50, -106,94
	Entity's Block location: World: (605,5,-107), Chunk: (at 13,0,5 in 37,-7; contains blocks 592,0,-112 to 607,255,-97), Region: (1,-1; contains chunks 32,-32 to 63,-1, blocks 512,0,-512 to 1023,255,-1)
	Entity's Momentum: 0,00, 0,00, 0,00

-- Renderer details --
Details:
	Assigned renderer: bgv@4d8cc8e9
	Location: 52,17,-0,12,-137,61 - World: (52,-1,-138), Chunk: (at 4,-1,6 in 3,-9; contains blocks 48,0,-144 to 63,255,-129), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,0,-512 to 511,255,-1)
	Rotation: 180.0
	Delta: 0.015778065
Stacktrace:
	at bgl.a(SourceFile:204)
	at bgl.a(SourceFile:184)
	at bfl.a(SourceFile:326)
	at bfe.a(SourceFile:845)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bdi['SunOfDarkness'/52, l='MpServer', x=553,33, y=5,62, z=30,67]]
	Chunk stats: MultiplayerChunkCache: 285
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (593,4,-47), Chunk: (at 1,0,1 in 37,-3; contains blocks 592,0,-48 to 607,255,-33), Region: (1,-1; contains chunks 32,-32 to 63,-1, blocks 512,0,-512 to 1023,255,-1)
	Level time: 1031719 game time, 7395 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: 29 total; [rs['Horse'/13, l='MpServer', x=534,88, y=4,00, z=78,72], rs['Horse'/14, l='MpServer', x=533,13, y=4,00, z=75,03], rs['Horse'/15, l='MpServer', x=531,56, y=4,00, z=73,46], rz['Sheep'/16, l='MpServer', x=534,13, y=4,00, z=85,09], ro['Bat'/19, l='MpServer', x=568,50, y=7,10, z=5,28], ub['Villager'/18, l='MpServer', x=552,50, y=5,00, z=25,50], ro['Bat'/21, l='MpServer', x=563,63, y=7,10, z=5,75], ro['Bat'/20, l='MpServer', x=571,75, y=7,10, z=8,25], ro['Bat'/23, l='MpServer', x=568,41, y=7,10, z=1,53], ro['Bat'/22, l='MpServer', x=565,75, y=7,10, z=4,75], tw['Zombie'/25, l='MpServer', x=563,84, y=5,00, z=25,28], ro['Bat'/24, l='MpServer', x=569,34, y=7,10, z=0,25], od['entity.ItemFrame.name'/31, l='MpServer', x=607,94, y=5,50, z=-101,50], od['entity.ItemFrame.name'/34, l='MpServer', x=607,94, y=5,50, z=-98,50], od['entity.ItemFrame.name'/35, l='MpServer', x=605,50, y=5,50, z=-98,06], od['entity.ItemFrame.name'/32, l='MpServer', x=607,94, y=5,50, z=-100,50], od['entity.ItemFrame.name'/33, l='MpServer', x=607,94, y=5,50, z=-99,50], od['entity.ItemFrame.name'/38, l='MpServer', x=607,94, y=5,50, z=-104,50], od['entity.ItemFrame.name'/39, l='MpServer', x=607,94, y=5,50, z=-105,50], od['entity.ItemFrame.name'/36, l='MpServer', x=606,50, y=5,50, z=-98,06], od['entity.ItemFrame.name'/37, l='MpServer', x=607,94, y=5,50, z=-103,50], od['entity.ItemFrame.name'/42, l='MpServer', x=605,50, y=5,50, z=-106,94], rr['Cow'/43, l='MpServer', x=603,75, y=4,00, z=-25,31], od['entity.ItemFrame.name'/40, l='MpServer', x=607,94, y=5,50, z=-106,50], od['entity.ItemFrame.name'/41, l='MpServer', x=606,50, y=5,50, z=-106,94], rr['Cow'/46, l='MpServer', x=614,91, y=4,00, z=-15,13], rr['Cow'/47, l='MpServer', x=632,25, y=4,00, z=-20,75], rr['Cow'/48, l='MpServer', x=633,41, y=4,00, z=15,78], bdi['SunOfDarkness'/52, l='MpServer', x=553,33, y=5,62, z=30,67]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at bdd.a(SourceFile:284)
	at atv.b(SourceFile:1761)
	at atv.d(SourceFile:628)
	at net.minecraft.client.main.Main.main(SourceFile:101)

-- System Details --
Details:
	Minecraft Version: 1.6.4
	Operating System: Mac OS X (x86_64) version 10.8.4
	Java Version: 1.6.0_51, Apple Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
	Memory: 114675744 bytes (109 MB) / 299601920 bytes (285 MB) up to 1060372480 bytes (1011 MB)
	JVM Flags: 1 total; -Xmx1G
	AABB Pool Size: 20675 (1157800 bytes; 1 MB) allocated, 282 (15792 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 1.6.4
	LWJGL: 2.9.0
	OpenGL: AMD Radeon HD 6970M OpenGL Engine GL version 2.1 ATI-1.8.18, ATI Technologies Inc.
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Pack: Default
	Current Language: English (UK)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 1648 (92288 bytes; 0 MB) allocated, 1647 (92232 bytes; 0 MB) used