Hopper: java.lang.ClassCastException: by cannot be cast to cg

java.lang.ClassCastException: by cannot be cast to cg
	at ye.r(SourceFile:356)
	at ye.a(SourceFile:436)
	at awy.a(SourceFile:188)
	at axm.a(SourceFile:580)
	at awy.a(SourceFile:168)
	at axp.a(SourceFile:31)
	at axm.a(SourceFile:529)

---- Minecraft Crash Report ----
// Shall we play a game?

Time: 9/24/13 11:04 AM
Description: Rendering screen

java.lang.ClassCastException: by cannot be cast to cg
	at ye.r(SourceFile:356)
	at ye.a(SourceFile:436)
	at awy.a(SourceFile:188)
	at axm.a(SourceFile:580)
	at awy.a(SourceFile:168)
	at axp.a(SourceFile:31)
	at axm.a(SourceFile:529)
	at bfe.b(SourceFile:718)
	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:
---------------------------------------------------------------------------------------

-- Head --
Stacktrace:
	at ye.r(SourceFile:356)
	at ye.a(SourceFile:436)
	at awy.a(SourceFile:188)
	at axm.a(SourceFile:580)
	at awy.a(SourceFile:168)
	at axp.a(SourceFile:31)
	at axm.a(SourceFile:529)

-- Screen render details --
Details:
	Screen name: axm
	Mouse location: Scaled: (141, 172). Absolute: (283, 134)
	Screen size: Scaled: (427, 240). Absolute: (854, 480). Scale factor of 2

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bdi['minemineminem'/74, l='MpServer', x=202.22, y=24.77, z=-156.41]]
	Chunk stats: MultiplayerChunkCache: 245
	Level seed: 0
	Level generator: ID 01 - flat, ver 0. Features enabled: false
	Level generator options: 
	Level spawn location: World: (161,4,-48), Chunk: (at 1,0,0 in 10,-3; contains blocks 160,0,-48 to 175,255,-33), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,0,-512 to 511,255,-1)
	Level time: 296258 game time, 141 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: 42 total; [rq['Chicken'/1, l='MpServer', x=124.56, y=4.00, z=-99.66], rq['Chicken'/2, l='MpServer', x=141.56, y=4.00, z=-77.56], oe['entity.LeashKnot.name'/71, l='MpServer', x=166.50, y=4.50, z=-117.50], ro['Bat'/64, l='MpServer', x=240.39, y=7.10, z=-144.25], ro['Bat'/65, l='MpServer', x=257.50, y=6.64, z=-106.33], ry['Pig'/6, l='MpServer', x=165.13, y=4.00, z=-199.88], rq['Chicken'/67, l='MpServer', x=260.05, y=4.00, z=-97.75], od['entity.ItemFrame.name'/7, l='MpServer', x=168.06, y=4.50, z=-185.50], od['entity.ItemFrame.name'/8, l='MpServer', x=168.06, y=4.50, z=-187.50], od['entity.ItemFrame.name'/9, l='MpServer', x=168.06, y=4.50, z=-189.50], od['entity.ItemFrame.name'/10, l='MpServer', x=171.06, y=5.50, z=-187.50], ub['trade shop worker'/11, l='MpServer', x=166.50, y=4.00, z=-185.50], oe['entity.LeashKnot.name'/72, l='MpServer', x=166.50, y=5.50, z=-117.50], ub['trade shop worker'/12, l='MpServer', x=166.31, y=4.00, z=-187.69], oe['entity.LeashKnot.name'/73, l='MpServer', x=166.50, y=6.50, z=-117.50], ub['trade shop worker'/13, l='MpServer', x=166.50, y=4.00, z=-189.50], ub['trade shop worker'/14, l='MpServer', x=166.50, y=4.00, z=-191.50], od['entity.ItemFrame.name'/15, l='MpServer', x=168.06, y=4.50, z=-191.50], rs['Horse'/17, l='MpServer', x=164.28, y=4.00, z=-119.00], rs['Horse'/16, l='MpServer', x=163.13, y=4.00, z=-117.16], rs['Horse'/18, l='MpServer', x=165.34, y=4.00, z=-116.59], bdi['minemineminem'/74, l='MpServer', x=202.22, y=24.77, z=-156.41], ro['Bat'/26, l='MpServer', x=182.99, y=5.30, z=-80.54], rs['Horse'/42, l='MpServer', x=194.94, y=4.00, z=-232.06], ry['Pig'/43, l='MpServer', x=196.91, y=4.00, z=-197.03], ry['Pig'/47, l='MpServer', x=218.69, y=4.00, z=-194.13], ro['Bat'/44, l='MpServer', x=199.53, y=6.11, z=-148.62], ro['Bat'/51, l='MpServer', x=218.19, y=11.14, z=-154.76], ro['Bat'/50, l='MpServer', x=219.19, y=6.10, z=-144.31], ro['Bat'/49, l='MpServer', x=219.65, y=4.47, z=-162.88], ro['Bat'/48, l='MpServer', x=216.50, y=6.10, z=-181.81], ry['Pig'/55, l='MpServer', x=237.69, y=5.00, z=-159.16], od['entity.ItemFrame.name'/54, l='MpServer', x=238.50, y=6.50, z=-163.94], ro['Bat'/52, l='MpServer', x=231.53, y=4.92, z=-108.63], ro['Bat'/59, l='MpServer', x=238.25, y=7.10, z=-144.25], ro['Bat'/58, l='MpServer', x=238.25, y=7.10, z=-147.22], ro['Bat'/57, l='MpServer', x=239.25, y=8.10, z=-144.25], ro['Bat'/56, l='MpServer', x=235.50, y=6.10, z=-151.03], ro['Bat'/63, l='MpServer', x=240.25, y=9.10, z=-144.59], ro['Bat'/62, l='MpServer', x=240.53, y=9.10, z=-144.31], ro['Bat'/61, l='MpServer', x=242.75, y=7.10, z=-144.25], rq['Chicken'/60, l='MpServer', x=225.55, y=4.00, z=-108.54]]
	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: Windows 7 (x86) version 6.1
	Java Version: 1.7.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
	Memory: 68098896 bytes (64 MB) / 252211200 bytes (240 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
	AABB Pool Size: 18931 (1060136 bytes; 1 MB) allocated, 2 (112 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: GeForce 8600 GT/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 Pack: Default
	Current Language: English (US)
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 233 (13048 bytes; 0 MB) allocated, 31 (1736 bytes; 0 MB) used