Hopper: java.lang.ClassCastException: atf cannot be cast to arj

java.lang.ClassCastException: atf cannot be cast to arj
	at bsz.a(SourceFile:1159)
	at bsu.a(SourceFile:39)
	at bsv.a(SourceFile:915)
	at bsv.a(SourceFile:870)
	at bvj.a(SourceFile:73)
	at bvj.a(SourceFile:27)

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

Time: 3/6/14 8:11 AM
Description: Rendering Block Entity

java.lang.ClassCastException: atf cannot be cast to arj
	at bsz.a(SourceFile:1159)
	at bsu.a(SourceFile:39)
	at bsv.a(SourceFile:915)
	at bsv.a(SourceFile:870)
	at bvj.a(SourceFile:73)
	at bvj.a(SourceFile:27)
	at bvd.a(SourceFile:105)
	at bvd.a(SourceFile:97)
	at bsi.a(SourceFile:479)
	at bsb.a(SourceFile:1150)
	at bsb.b(SourceFile:937)
	at ben.ai(SourceFile:827)
	at ben.f(SourceFile:754)
	at net.minecraft.client.main.Main.main(SourceFile:121)


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

-- Head --
Stacktrace:
	at bsz.a(SourceFile:1159)
	at bsu.a(SourceFile:39)
	at bsv.a(SourceFile:915)
	at bsv.a(SourceFile:870)
	at bvj.a(SourceFile:73)
	at bvj.a(SourceFile:27)

-- Block Entity Details --
Details:
	Name: Piston // atg
	Block type: ID #36 (tile.null // atf)
	Block data value: 0 / 0x0 / 0b0000
	Block location: World: (-246,58,243), Chunk: (at 10,3,3 in -16,15; contains blocks -256,0,240 to -241,255,255), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Actual block type: ID #36 (tile.null // atf)
	Actual block data value: 0 / 0x0 / 0b0000
Stacktrace:
	at bvd.a(SourceFile:105)
	at bvd.a(SourceFile:97)
	at bsi.a(SourceFile:479)
	at bsb.a(SourceFile:1150)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [brr['ForceablePlace'/204, l='MpServer', x=-247.75, y=58.00, z=243.50]]
	Chunk stats: MultiplayerChunkCache: 1089, 1089
	Level seed: 0
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: -12.00,64.00,236.00 - World: (-12,64,236), Chunk: (at 4,4,12 in -1,14; contains blocks -16,0,224 to -1,255,239), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
	Level time: 676560 game time, 698483 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
	Forced entities: 104 total; [xw['Cow'/1, l='MpServer', x=-194.75, y=77.00, z=179.31], xw['Cow'/2, l='MpServer', x=-197.53, y=78.00, z=190.83], xw['Cow'/3, l='MpServer', x=-207.47, y=65.00, z=232.44], xw['Cow'/4, l='MpServer', x=-199.91, y=68.00, z=249.09], yh['Squid'/5, l='MpServer', x=-195.53, y=59.66, z=271.22], za['item.item.frame'/1644, l='MpServer', x=-263.91, y=56.91, z=239.21], za['item.item.shears'/1645, l='MpServer', x=-264.78, y=60.00, z=236.00], xw['Cow'/15, l='MpServer', x=-176.06, y=76.00, z=175.25], xw['Cow'/17, l='MpServer', x=-186.53, y=74.00, z=184.69], xw['Cow'/16, l='MpServer', x=-186.81, y=71.00, z=175.19], xw['Cow'/18, l='MpServer', x=-191.09, y=76.00, z=206.00], xw['Cow'/21, l='MpServer', x=-171.28, y=72.95, z=227.52], xw['Cow'/20, l='MpServer', x=-181.28, y=72.00, z=228.78], yd['Pig'/23, l='MpServer', x=-180.09, y=73.00, z=226.19], xw['Cow'/22, l='MpServer', x=-176.91, y=73.00, z=226.16], xw['Cow'/25, l='MpServer', x=-184.28, y=68.00, z=246.28], yh['Squid'/27, l='MpServer', x=-188.63, y=57.53, z=264.50], xw['Cow'/26, l='MpServer', x=-176.50, y=68.47, z=239.55], yd['Pig'/29, l='MpServer', x=-190.97, y=63.00, z=272.09], yh['Squid'/28, l='MpServer', x=-186.13, y=62.50, z=267.41], yd['Pig'/31, l='MpServer', x=-181.50, y=72.00, z=289.69], xt['Bat'/516, l='MpServer', x=-229.44, y=26.44, z=312.95], xw['Cow'/35, l='MpServer', x=-170.31, y=79.00, z=207.75], yd['Pig'/33, l='MpServer', x=-186.06, y=67.00, z=316.03], yd['Pig'/38, l='MpServer', x=-179.03, y=77.00, z=227.44], yd['Pig'/39, l='MpServer', x=-170.69, y=80.00, z=226.00], xt['Bat'/515, l='MpServer', x=-212.94, y=26.00, z=313.00], yd['Pig'/43, l='MpServer', x=-173.03, y=69.00, z=297.16], brr['ForceablePlace'/204, l='MpServer', x=-247.75, y=58.00, z=243.50], xv['Chicken'/522, l='MpServer', x=-226.53, y=61.22, z=323.41], xw['Cow'/533, l='MpServer', x=-211.59, y=17.00, z=239.25], xw['Cow'/532, l='MpServer', x=-209.81, y=76.00, z=188.63], xw['Cow'/535, l='MpServer', x=-208.59, y=65.00, z=233.44], xw['Cow'/534, l='MpServer', x=-208.91, y=70.00, z=224.03], xt['Bat'/537, l='MpServer', x=-211.07, y=77.61, z=277.67], xw['Cow'/536, l='MpServer', x=-219.97, y=55.00, z=259.16], za['item.item.feather'/1038, l='MpServer', x=-254.00, y=58.00, z=251.75], za['item.item.chickenRaw'/1041, l='MpServer', x=-255.75, y=58.00, z=255.19], za['item.item.chickenRaw'/1044, l='MpServer', x=-254.00, y=59.00, z=253.19], za['item.item.leather'/1548, l='MpServer', x=-247.16, y=74.00, z=220.37], za['item.item.beefRaw'/1550, l='MpServer', x=-247.50, y=74.00, z=220.50], xx['Horse'/580, l='MpServer', x=-252.66, y=57.50, z=247.25], xt['Bat'/368, l='MpServer', x=-329.19, y=16.64, z=268.42], ud['entity.LeashKnot.name'/582, l='MpServer', x=-246.50, y=62.50, z=237.50], ud['entity.LeashKnot.name'/583, l='MpServer', x=-252.50, y=61.50, z=237.50], ud['entity.LeashKnot.name'/584, l='MpServer', x=-252.50, y=61.50, z=237.50], ud['entity.LeashKnot.name'/585, l='MpServer', x=-252.50, y=61.50, z=237.50], ud['entity.LeashKnot.name'/586, l='MpServer', x=-252.50, y=61.50, z=237.50], za['item.item.feather'/1062, l='MpServer', x=-228.16, y=46.00, z=259.72], za['item.item.chickenRaw'/1063, l='MpServer', x=-228.38, y=46.00, z=259.84], xt['Bat'/376, l='MpServer', x=-321.16, y=18.00, z=276.35], xw['Cow'/364, l='MpServer', x=-328.41, y=64.00, z=226.34], xw['Cow'/367, l='MpServer', x=-324.47, y=69.00, z=243.69], za['item.item.leather'/1553, l='MpServer', x=-237.97, y=81.00, z=217.03], za['item.item.leather'/1552, l='MpServer', x=-237.50, y=81.00, z=216.13], xw['Cow'/362, l='MpServer', x=-328.22, y=66.00, z=211.09], za['item.item.beefRaw'/1554, l='MpServer', x=-237.91, y=81.00, z=217.06], xw['Cow'/406, l='MpServer', x=-301.56, y=68.00, z=199.56], xw['Cow'/407, l='MpServer', x=-291.56, y=70.00, z=199.13], xt['Bat'/391, l='MpServer', x=-317.75, y=15.10, z=267.75], xw['Cow'/390, l='MpServer', x=-307.94, y=68.00, z=221.44], xw['Cow'/388, l='MpServer', x=-312.66, y=71.00, z=191.38], xt['Bat'/440, l='MpServer', x=-284.56, y=39.10, z=240.59], za['item.item.bone'/442, l='MpServer', x=-285.84, y=67.00, z=269.22], xt['Bat'/444, l='MpServer', x=-280.75, y=37.10, z=292.75], xt['Bat'/447, l='MpServer', x=-271.34, y=29.51, z=301.28], xw['Cow'/438, l='MpServer', x=-272.47, y=64.00, z=174.22], za['item.item.bone'/439, l='MpServer', x=-273.13, y=78.00, z=206.88], xv['Chicken'/205, l='MpServer', x=-256.56, y=58.00, z=252.72], xw['Cow'/478, l='MpServer', x=-255.16, y=81.00, z=196.00], xv['Chicken'/476, l='MpServer', x=-246.53, y=83.69, z=194.45], xv['Chicken'/206, l='MpServer', x=-255.88, y=58.00, z=253.78], za['item.item.egg'/477, l='MpServer', x=-240.84, y=85.00, z=192.88], uc['entity.ItemFrame.name'/467, l='MpServer', x=-256.50, y=59.50, z=254.97], ye['Sheep'/463, l='MpServer', x=-267.56, y=58.00, z=238.97], xv['Chicken'/220, l='MpServer', x=-253.97, y=58.00, z=254.19], ye['Sheep'/462, l='MpServer', x=-265.94, y=58.00, z=237.91], xv['Chicken'/221, l='MpServer', x=-254.50, y=58.00, z=254.88], xw['Cow'/461, l='MpServer', x=-270.47, y=61.02, z=231.32], xw['Cow'/460, l='MpServer', x=-270.47, y=62.18, z=231.41], xv['Chicken'/216, l='MpServer', x=-255.53, y=58.00, z=255.59], xw['Cow'/459, l='MpServer', x=-269.51, y=79.69, z=203.50], xv['Chicken'/217, l='MpServer', x=-253.25, y=58.00, z=253.22], xw['Cow'/458, l='MpServer', x=-269.16, y=86.00, z=204.00], xw['Cow'/457, l='MpServer', x=-257.22, y=77.00, z=172.16], xv['Chicken'/218, l='MpServer', x=-255.16, y=58.00, z=255.16], xv['Chicken'/219, l='MpServer', x=-253.75, y=58.00, z=253.69], xv['Chicken'/212, l='MpServer', x=-254.81, y=58.00, z=254.31], xv['Chicken'/214, l='MpServer', x=-253.91, y=58.00, z=254.78], yd['Pig'/208, l='MpServer', x=-248.47, y=59.00, z=237.28], xv['Chicken'/209, l='MpServer', x=-255.28, y=58.00, z=253.63], xv['Chicken'/210, l='MpServer', x=-254.53, y=58.00, z=253.41], xw['Cow'/508, l='MpServer', x=-226.47, y=25.00, z=263.75], xt['Bat'/510, l='MpServer', x=-236.50, y=30.71, z=306.04], uc['entity.ItemFrame.name'/506, l='MpServer', x=-224.03, y=57.50, z=245.50], yd['Pig'/507, l='MpServer', x=-234.97, y=68.00, z=249.38], yh['Squid'/493, l='MpServer', x=-248.22, y=61.94, z=307.16], yh['Squid'/494, l='MpServer', x=-256.91, y=62.00, z=305.91], yd['Pig'/485, l='MpServer', x=-251.13, y=62.00, z=287.63], xx['Horse'/484, l='MpServer', x=-254.22, y=58.00, z=238.50], xw['Cow'/486, l='MpServer', x=-241.56, y=57.00, z=284.25], xx['Donkey'/481, l='MpServer', x=-251.94, y=58.00, z=237.75], xx['Donkey'/483, l='MpServer', x=-252.50, y=58.00, z=239.53], xx['Donkey'/482, l='MpServer', x=-250.25, y=58.00, z=237.91]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at bpn.a(SourceFile:308)
	at ben.b(SourceFile:2068)
	at ben.f(SourceFile:763)
	at net.minecraft.client.main.Main.main(SourceFile:121)

-- System Details --
Details:
	Minecraft Version: 14w10a
	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: 4420559768 bytes (4215 MB) / 5145886720 bytes (4907 MB) up to 9544663040 bytes (9102 MB)
	JVM Flags: 3 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xms5G -Xmx10G
	IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
	Launched Version: 14w10a
	LWJGL: 2.9.1
	OpenGL: GeForce GTX 560M/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: [Music]
	Current Language: Canadian English (CA)
	Profiler Position: N/A (disabled)
	Anisotropic Filtering: On (16)