[MC-92144] Hopper: java.lang.ClassCastException: ahw cannot be cast to ahn

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-2593735/

Crash:

java.lang.ClassCastException: ahw cannot be cast to ahn
	at aqo.a(SourceFile:148)
	at aqv$a.c(SourceFile:373)
	at aym.a(SourceFile:107)
	at aym.a(SourceFile:83)
	at ayk.a(SourceFile:82)
	at ayk.a(SourceFile:40)
	at ayk.a(SourceFile:30)
	at vb.a(SourceFile:89)
	at va.a(SourceFile:67)
	at va.a(SourceFile:76)
	at vb.a(SourceFile:127)
	at ul.e(SourceFile:104)
	at th.a(SourceFile:129)
	at ry.cd(SourceFile:631)
	at rx.n(SourceFile:1688)
	at ry.n(SourceFile:484)
	at rl.n(SourceFile:134)
	at vs.n(SourceFile:41)
	at vt.n(SourceFile:80)
	at rx.m(SourceFile:1550)
	at ry.m(SourceFile:275)
	at ahn.a(SourceFile:1481)
	at lq.a(SourceFile:719)
	at ahn.g(SourceFile:1459)

The following is the first clean report made public about this crash:

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

Time: 11/5/15 6:27 AM
Description: Ticking entity

java.lang.ClassCastException: ahw cannot be cast to ahn
	at aqo.a(SourceFile:148)
	at aqv$a.c(SourceFile:373)
	at aym.a(SourceFile:107)
	at aym.a(SourceFile:83)
	at ayk.a(SourceFile:82)
	at ayk.a(SourceFile:40)
	at ayk.a(SourceFile:30)
	at vb.a(SourceFile:89)
	at va.a(SourceFile:67)
	at va.a(SourceFile:76)
	at vb.a(SourceFile:127)
	at ul.e(SourceFile:104)
	at th.a(SourceFile:129)
	at ry.cd(SourceFile:631)
	at rx.n(SourceFile:1688)
	at ry.n(SourceFile:484)
	at rl.n(SourceFile:134)
	at vs.n(SourceFile:41)
	at vt.n(SourceFile:80)
	at rx.m(SourceFile:1550)
	at ry.m(SourceFile:275)
	at ahn.a(SourceFile:1481)
	at lq.a(SourceFile:719)
	at ahn.g(SourceFile:1459)
	at ahn.k(SourceFile:1349)
	at lq.k(SourceFile:552)
	at net.minecraft.server.MinecraftServer.D(SourceFile:618)
	at net.minecraft.server.MinecraftServer.C(SourceFile:546)
	at bxx.C(SourceFile:154)
	at net.minecraft.server.MinecraftServer.run(SourceFile:450)
	at java.lang.Thread.run(Thread.java:745)


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

-- Head --
Stacktrace:
	at aqo.a(SourceFile:148)
	at aqv$a.c(SourceFile:373)
	at aym.a(SourceFile:107)
	at aym.a(SourceFile:83)
	at ayk.a(SourceFile:82)
	at ayk.a(SourceFile:40)
	at ayk.a(SourceFile:30)
	at vb.a(SourceFile:89)
	at va.a(SourceFile:67)
	at va.a(SourceFile:76)
	at vb.a(SourceFile:127)
	at ul.e(SourceFile:104)
	at th.a(SourceFile:129)
	at ry.cd(SourceFile:631)
	at rx.n(SourceFile:1688)
	at ry.n(SourceFile:484)
	at rl.n(SourceFile:134)
	at vs.n(SourceFile:41)
	at vt.n(SourceFile:80)
	at rx.m(SourceFile:1550)
	at ry.m(SourceFile:275)
	at ahn.a(SourceFile:1481)
	at lq.a(SourceFile:719)
	at ahn.g(SourceFile:1459)

-- Entity being ticked --
Details:
	Entity Type: Chicken (vt)
	Entity ID: 248
	Entity Name: Chicken
	Entity's Exact location: -128.17, 64.00, -369.50
	Entity's Block location: World: (-129,64,-370), Chunk: (at 15,4,14 in -9,-24; contains blocks -144,0,-384 to -129,255,-369), Region: (-1,-1; contains chunks -32,-32 to -1,-1, blocks -512,0,-512 to -1,255,-1)
	Entity's Momentum: 0.00, -0.08, 0.00
	Entity's Passengers: []
	Entity's Vehicle: ~~ERROR~~ NullPointerException: null
Stacktrace:
	at ahn.k(SourceFile:1349)
	at lq.k(SourceFile:552)

-- Affected level --
Details:
	Level name: MC 1_9 Survival World
	All players: 1 total; [ls['iEpicSanikBoom'/134, l='MC 1_9 Survival World', x=-126.49, y=66.50, z=-364.48]]
	Chunk stats: ServerChunkCache: 461 Drop: 0
	Level seed: 1376918767107532030
	Level generator: ID 00 - default, ver 1. Features enabled: true
	Level generator options: 
	Level spawn location: World: (216,64,256), Chunk: (at 8,4,0 in 13,16; contains blocks 208,0,256 to 223,255,271), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
	Level time: 546690 game time, 852072 day time
	Level dimension: 0
	Level storage version: 0x04ABD - Anvil
	Level weather: Rain time: 36826 (now: false), thunder time: 157309 (now: false)
	Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Stacktrace:
	at net.minecraft.server.MinecraftServer.D(SourceFile:618)
	at net.minecraft.server.MinecraftServer.C(SourceFile:546)
	at bxx.C(SourceFile:154)
	at net.minecraft.server.MinecraftServer.run(SourceFile:450)
	at java.lang.Thread.run(Thread.java:745)

-- System Details --
Details:
	Minecraft Version: 15w45a
	Operating System: Mac OS X (x86_64) version 10.10.5
	Java Version: 1.8.0_60, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 121330000 bytes (115 MB) / 319193088 bytes (304 MB) up to 1060372480 bytes (1011 MB)
	JVM Flags: 5 total; -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
	IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
	Profiler Position: N/A (disabled)
	Player Count: 1 / 8; [ls['iEpicSanikBoom'/134, l='MC 1_9 Survival World', x=-126.49, y=66.50, z=-364.48]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.