Hopper: java.lang.IncompatibleClassChangeError: Class [B does not implement the requested interface java.util.Map

java.lang.IncompatibleClassChangeError: Class [B does not implement the requested interface java.util.Map
	at pd.i(SourceFile:107)
	at pd.a(SourceFile:79)
	at oc.f(SourceFile:1344)
	at oc.ai(SourceFile:1308)
	at oc.d(SourceFile:453)
	at bgd.o_(SourceFile:116)
	at bge.a(SourceFile:63)
	at avx.m(SourceFile:1448)
	at avx.V(SourceFile:686)
	at avx.e(SourceFile:642)
	at net.minecraft.client.main.Main.main(SourceFile:103)

---- Minecraft Crash Report ----
// On the bright side, I bought you a teddy bear!

Time: 9/6/13 2:45 PM
Description: Getting synched entity data

java.lang.IncompatibleClassChangeError: Class [B does not implement the requested interface java.util.Map
	at pd.i(SourceFile:107)
	at pd.a(SourceFile:79)
	at oc.f(SourceFile:1344)
	at oc.ai(SourceFile:1308)
	at oc.d(SourceFile:453)
	at bgd.o_(SourceFile:116)
	at bge.a(SourceFile:63)
	at avx.m(SourceFile:1448)
	at avx.V(SourceFile:686)
	at avx.e(SourceFile:642)
	at net.minecraft.client.main.Main.main(SourceFile:103)


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

-- Synched entity data --
Details:
	Data ID: 0
Stacktrace:
	at pd.i(SourceFile:107)
	at pd.a(SourceFile:79)
	at oc.f(SourceFile:1344)
	at oc.ai(SourceFile:1308)
	at oc.d(SourceFile:453)
	at bgd.o_(SourceFile:116)

-- Particle being ticked --
Details:
	Particle: bfl, Pos (307.8195350870116,67.10000000149012,276.2506902038077), RGBA (1.0,1.0,1.0,1.0), Age 17
	Particle Type: ITEM_TEXTURE
Stacktrace:
	at bge.a(SourceFile:63)

-- Affected level --
Details:
	Level name: MpServer
	All players: 1 total; [bfg['EpicOfAwesomness'/174, l='MpServer', x=307.70, y=69.62, z=278.51]]
	Chunk stats: MultiplayerChunkCache: 350, 350
	Level seed: 0
	Level generator: ID 00 - default, ver 1. Features enabled: false
	Level generator options: 
	Level spawn location: World: (188,64,256), Chunk: (at 12,4,0 in 11,16; contains blocks 176,0,256 to 191,255,271), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 19950 game time, 19950 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: 132 total; [un['Zombie'/47812, l='MpServer', x=348.41, y=66.00, z=234.16], so['Sheep'/85, l='MpServer', x=235.50, y=63.00, z=325.50], so['Sheep'/87, l='MpServer', x=232.50, y=64.00, z=322.50], so['Sheep'/86, l='MpServer', x=236.50, y=63.00, z=327.50], so['Sheep'/93, l='MpServer', x=260.50, y=71.00, z=275.50], so['Sheep'/92, l='MpServer', x=263.50, y=69.00, z=279.50], so['Sheep'/95, l='MpServer', x=253.50, y=71.00, z=276.50], so['Sheep'/94, l='MpServer', x=256.50, y=75.00, z=275.50], so['Sheep'/89, l='MpServer', x=247.72, y=71.00, z=228.78], so['Sheep'/88, l='MpServer', x=246.50, y=71.00, z=234.19], so['Sheep'/91, l='MpServer', x=262.22, y=72.00, z=234.13], so['Sheep'/90, l='MpServer', x=261.66, y=75.00, z=246.44], so['Sheep'/98, l='MpServer', x=262.81, y=69.00, z=281.88], so['Sheep'/99, l='MpServer', x=261.44, y=68.00, z=285.34], so['Sheep'/96, l='MpServer', x=261.31, y=66.00, z=288.56], so['Sheep'/97, l='MpServer', x=263.88, y=66.00, z=288.50], so['Sheep'/127, l='MpServer', x=294.47, y=79.00, z=311.88], so['Sheep'/126, l='MpServer', x=300.91, y=78.00, z=312.59], so['Sheep'/125, l='MpServer', x=299.13, y=78.00, z=308.06], so['Sheep'/124, l='MpServer', x=297.91, y=79.00, z=312.50], sg['Cow'/137, l='MpServer', x=319.53, y=70.00, z=331.53], sg['Cow'/136, l='MpServer', x=319.53, y=71.00, z=330.47], sd['Bat'/50513, l='MpServer', x=275.69, y=33.13, z=219.58], sg['Cow'/139, l='MpServer', x=318.47, y=71.00, z=331.53], sd['Bat'/50512, l='MpServer', x=270.71, y=34.00, z=218.75], sg['Cow'/138, l='MpServer', x=319.50, y=72.00, z=329.47], so['Sheep'/129, l='MpServer', x=291.69, y=65.00, z=272.84], so['Sheep'/128, l='MpServer', x=317.81, y=64.00, z=273.78], so['Sheep'/131, l='MpServer', x=338.03, y=65.00, z=253.97], so['Sheep'/130, l='MpServer', x=310.97, y=68.00, z=252.06], sg['Cow'/133, l='MpServer', x=321.75, y=65.00, z=338.22], sg['Cow'/132, l='MpServer', x=319.22, y=66.00, z=338.47], sg['Cow'/135, l='MpServer', x=320.81, y=65.00, z=339.81], sg['Cow'/134, l='MpServer', x=319.47, y=65.00, z=340.75], so['Sheep'/146, l='MpServer', x=326.94, y=64.00, z=285.03], so['Sheep'/147, l='MpServer', x=328.88, y=66.00, z=290.28], so['Sheep'/148, l='MpServer', x=333.50, y=66.00, z=292.09], so['Sheep'/149, l='MpServer', x=332.97, y=66.00, z=289.09], so['Sheep'/171, l='MpServer', x=383.53, y=68.00, z=284.34], ui['Skeleton'/50544, l='MpServer', x=362.50, y=25.00, z=350.50], so['Sheep'/170, l='MpServer', x=365.09, y=64.00, z=256.03], sg['Cow'/169, l='MpServer', x=341.72, y=64.00, z=348.47], sg['Cow'/168, l='MpServer', x=347.50, y=64.00, z=333.50], un['Zombie'/50549, l='MpServer', x=323.50, y=43.00, z=301.50], un['Zombie'/50548, l='MpServer', x=322.50, y=43.00, z=303.50], so['Sheep'/173, l='MpServer', x=367.56, y=63.00, z=279.34], so['Sheep'/172, l='MpServer', x=369.31, y=63.00, z=279.81], sf['Chicken'/163, l='MpServer', x=372.59, y=69.00, z=214.63], sf['Chicken'/162, l='MpServer', x=364.44, y=68.00, z=211.44], sg['Cow'/167, l='MpServer', x=342.94, y=64.00, z=330.13], sg['Cow'/166, l='MpServer', x=345.31, y=64.00, z=338.41], sf['Chicken'/165, l='MpServer', x=362.59, y=60.36, z=230.56], sf['Chicken'/164, l='MpServer', x=312.56, y=68.00, z=258.59], tx['Enderman'/50537, l='MpServer', x=343.30, y=22.00, z=331.05], tx['Enderman'/50538, l='MpServer', x=343.59, y=22.00, z=331.98], tx['Enderman'/50539, l='MpServer', x=345.50, y=22.00, z=333.50], tx['Enderman'/50540, l='MpServer', x=348.52, y=22.00, z=332.66], tw['Creeper'/45708, l='MpServer', x=340.50, y=66.00, z=204.94], ui['Skeleton'/45712, l='MpServer', x=347.66, y=65.00, z=238.16], tw['Creeper'/50447, l='MpServer', x=305.50, y=44.00, z=198.50], bfg['EpicOfAwesomness'/174, l='MpServer', x=307.70, y=69.62, z=278.51], tw['Creeper'/47669, l='MpServer', x=309.22, y=66.00, z=262.97], sd['Bat'/50488, l='MpServer', x=283.94, y=52.00, z=264.69], sr['Squid'/50379, l='MpServer', x=272.50, y=62.00, z=327.50], sr['Squid'/50381, l='MpServer', x=263.16, y=60.22, z=340.50], sr['Squid'/50380, l='MpServer', x=264.34, y=62.38, z=338.16], sr['Squid'/50382, l='MpServer', x=266.47, y=61.03, z=332.09], ui['Skeleton'/41570, l='MpServer', x=366.22, y=63.00, z=276.16], un['Zombie'/50430, l='MpServer', x=234.50, y=68.00, z=209.50], ui['Skeleton'/50344, l='MpServer', x=321.50, y=43.00, z=300.50], ui['Skeleton'/50366, l='MpServer', x=374.91, y=23.00, z=202.31], un['Zombie'/50263, l='MpServer', x=363.50, y=76.00, z=302.50], uk['Spider'/50285, l='MpServer', x=381.78, y=71.00, z=199.06], tw['Creeper'/47896, l='MpServer', x=383.50, y=50.00, z=249.50], sd['Bat'/50228, l='MpServer', x=241.50, y=36.48, z=200.46], uk['Spider'/43515, l='MpServer', x=342.59, y=65.00, z=242.47], ui['Skeleton'/43328, l='MpServer', x=370.50, y=60.21, z=228.91], tw['Creeper'/45411, l='MpServer', x=305.13, y=65.00, z=223.28], ui['Skeleton'/47458, l='MpServer', x=263.50, y=77.00, z=251.50], op['Experience Orb'/47472, l='MpServer', x=327.84, y=65.25, z=236.22], op['Experience Orb'/47473, l='MpServer', x=328.59, y=65.25, z=237.03], un['Zombie'/48772, l='MpServer', x=337.56, y=65.00, z=248.09], un['Zombie'/48771, l='MpServer', x=351.50, y=64.00, z=254.44], ui['Skeleton'/48768, l='MpServer', x=354.50, y=63.00, z=271.50], ui['Skeleton'/48769, l='MpServer', x=360.25, y=63.00, z=277.34], ui['Skeleton'/49584, l='MpServer', x=382.50, y=66.00, z=328.50], tw['Creeper'/49580, l='MpServer', x=326.53, y=72.00, z=301.13], sd['Bat'/48858, l='MpServer', x=298.58, y=15.55, z=229.53], un['Zombie'/49616, l='MpServer', x=258.50, y=73.00, z=241.50], ui['Skeleton'/42860, l='MpServer', x=300.44, y=66.00, z=218.94], uk['Spider'/49435, l='MpServer', x=380.50, y=73.00, z=268.50], un['Zombie'/49432, l='MpServer', x=308.27, y=67.00, z=276.23], un['Zombie'/49430, l='MpServer', x=309.44, y=66.50, z=275.15], tw['Creeper'/48653, l='MpServer', x=297.50, y=65.00, z=224.50], sd['Bat'/49316, l='MpServer', x=327.64, y=20.88, z=317.16], tw['Creeper'/40378, l='MpServer', x=380.25, y=64.00, z=244.88], un['Zombie'/46914, l='MpServer', x=273.50, y=19.00, z=206.50], sd['Bat'/47005, l='MpServer', x=307.50, y=28.10, z=218.53], tw['Creeper'/48959, l='MpServer', x=293.50, y=67.00, z=294.50], un['Zombie'/49226, l='MpServer', x=342.50, y=78.00, z=309.50], ui['Skeleton'/49229, l='MpServer', x=323.50, y=69.00, z=294.50], tw['Creeper'/49230, l='MpServer', x=337.50, y=67.00, z=299.50], un['Zombie'/49218, l='MpServer', x=305.50, y=32.00, z=276.50], un['Zombie'/49219, l='MpServer', x=305.50, y=32.00, z=275.50], un['Zombie'/47040, l='MpServer', x=383.34, y=66.00, z=330.34], uk['Spider'/50054, l='MpServer', x=228.00, y=69.00, z=216.72], tw['Creeper'/50053, l='MpServer', x=231.50, y=69.00, z=215.50], uk['Spider'/48366, l='MpServer', x=360.72, y=64.65, z=234.97], un['Zombie'/50156, l='MpServer', x=364.50, y=38.00, z=198.50], tj['item.item.egg'/50152, l='MpServer', x=311.47, y=67.13, z=261.09], sd['Bat'/48353, l='MpServer', x=276.38, y=21.10, z=205.75], tw['Creeper'/48139, l='MpServer', x=309.41, y=67.00, z=244.00], ui['Skeleton'/48138, l='MpServer', x=297.50, y=65.00, z=234.50], sd['Bat'/49920, l='MpServer', x=288.25, y=40.89, z=255.03], ui['Skeleton'/48137, l='MpServer', x=303.16, y=65.00, z=238.31], sd['Bat'/49921, l='MpServer', x=287.34, y=40.95, z=246.25], ui['Skeleton'/50043, l='MpServer', x=382.50, y=68.00, z=321.50], sd['Bat'/49902, l='MpServer', x=272.99, y=22.18, z=205.72], sd['Bat'/49919, l='MpServer', x=298.78, y=42.02, z=264.09], sd['Bat'/48591, l='MpServer', x=303.19, y=43.73, z=223.09], tw['Creeper'/48585, l='MpServer', x=269.50, y=38.00, z=232.50], uk['Spider'/48582, l='MpServer', x=305.25, y=28.00, z=226.59], sd['Bat'/48594, l='MpServer', x=291.72, y=38.76, z=257.28], tj['item.item.seeds'/46489, l='MpServer', x=352.25, y=65.13, z=241.13], sd['Bat'/49692, l='MpServer', x=282.79, y=14.15, z=234.31], uk['Spider'/48498, l='MpServer', x=303.28, y=68.78, z=278.66], un['Zombie'/48499, l='MpServer', x=294.41, y=65.00, z=291.50], un['Zombie'/48506, l='MpServer', x=286.95, y=65.00, z=287.35], tx['Enderman'/48454, l='MpServer', x=343.13, y=41.00, z=328.34], uk['Spider'/48457, l='MpServer', x=342.72, y=43.00, z=326.97], tx['Enderman'/48456, l='MpServer', x=344.91, y=41.00, z=329.91], sd['Bat'/48468, l='MpServer', x=324.76, y=21.97, z=307.26]]
	Retry entities: 0 total; []
	Server brand: vanilla
	Server type: Integrated singleplayer server
Stacktrace:
	at bfb.a(SourceFile:285)
	at avx.b(SourceFile:1813)
	at avx.e(SourceFile:651)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 13w36a
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.7.0_15, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
	Memory: 89639880 bytes (85 MB) / 271695872 bytes (259 MB) up to 518979584 bytes (494 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
	AABB Pool Size: 5336 (298816 bytes; 0 MB) allocated, 1850 (103600 bytes; 0 MB) used
	Suspicious classes: [com.ibm.icu.text.ArabicShapingException], [gnu.trove.TIntCollection], [gnu.trove.impl.HashFunctions, PrimeFinder], [gnu.trove.impl.hash.THash, TPrimitiveHash, TIntIntHash], [gnu.trove.iterator.TIterator, TAdvancingIterator, TIntIntIterator], [gnu.trove.map.TIntIntMap], [gnu.trove.map.hash.TIntIntHashMap], [gnu.trove.procedure.TIntIntProcedure], [gnu.trove.set.TIntSet]
	IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
	Launched Version: 13w36a
	LWJGL: 2.9.0
	OpenGL: AMD Radeon(TM) HD 6480G GL version 4.1.11156 Compatibility Profile Context, ATI Technologies Inc.
	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: 2177 (121912 bytes; 0 MB) allocated, 544 (30464 bytes; 0 MB) used