Hopper: java.lang.ClassCastException: ayv cannot be cast to azh

java.lang.ClassCastException: ayv cannot be cast to azh
	at amj.b(SourceFile:42)
	at eg.a(SourceFile:12)
	at auw.d(SourceFile:105)
	at auw.c(SourceFile:131)

---- Minecraft Crash Report ----
// I feel sad now :(

Time: 08/08/14 16:16
Description: Exception while ticking a block

java.lang.ClassCastException: ayv cannot be cast to azh
	at amj.b(SourceFile:42)
	at eg.a(SourceFile:12)
	at auw.d(SourceFile:105)
	at auw.c(SourceFile:131)
	at qr.a(SourceFile:527)
	at qr.c(SourceFile:199)
	at net.minecraft.server.MinecraftServer.y(SourceFile:598)
	at net.minecraft.server.MinecraftServer.x(SourceFile:530)
	at cxz.x(SourceFile:155)
	at net.minecraft.server.MinecraftServer.run(SourceFile:446)
	at java.lang.Thread.run(Unknown Source)


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

-- Head --
Stacktrace:
	at amj.b(SourceFile:42)
	at eg.a(SourceFile:12)
	at auw.d(SourceFile:105)
	at auw.c(SourceFile:131)

-- Block being ticked --
Details:
	Block: minecraft:dispenser[facing=south,triggered=true]
	Block location: World: (403,17,798), Chunk: (at 3,1,14 in 25,49; contains blocks 400,0,784 to 415,255,799), Region: (0,1; contains chunks 0,32 to 31,63, blocks 0,0,512 to 511,255,1023)
Stacktrace:
	at qr.a(SourceFile:527)
	at qr.c(SourceFile:199)

-- Affected level --
Details:
	Level name: glass world
	All players: 1 total; [qu['fafastars'/10, l='glass world', x=403,44, y=16,00, z=801,49]]
	Chunk stats: ServerChunkCache: 1250 Drop: 0
	Level seed: -8258886349256977723
	Level generator: ID 01 - flat, ver 0. Features enabled: true
	Level generator options: 3;7,95,95,95,95,95,95,95,95,95,95,95,95,95,95,95;1;
	Level spawn location: -87,00,15,00,-157,00 - World: (-87,15,-157), Chunk: (at 9,0,3 in -6,-10; contains blocks -96,0,-160 to -81,255,-145), Region: (-1,-1; contains chunks -32,-32 to -1,-1, blocks -512,0,-512 to -1,255,-1)
	Level time: 57478 game time, 5773 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 1 (now: false), thunder time: 1 (now: false)
	Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: true
Stacktrace:
	at net.minecraft.server.MinecraftServer.y(SourceFile:598)
	at net.minecraft.server.MinecraftServer.x(SourceFile:530)
	at cxz.x(SourceFile:155)
	at net.minecraft.server.MinecraftServer.run(SourceFile:446)
	at java.lang.Thread.run(Unknown Source)

-- System Details --
Details:
	Minecraft Version: 14w32d
	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: 70884864 bytes (67 MB) / 288247808 bytes (274 MB) up to 1060372480 bytes (1011 MB)
	JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Profiler Position: N/A (disabled)
	Player Count: 1 / 8; [qu['fafastars'/10, l='glass world', x=403,44, y=16,00, z=801,49]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.