Hopper: java.lang.ClassCastException: ans cannot be cast to ani

java.lang.ClassCastException: ans cannot be cast to ani
	at aij.m(SourceFile:250)
	at aij.a(SourceFile:240)
	at mn.a(SourceFile:241)
	at mx.a(SourceFile:365)
	at jc.a(SourceFile:60)
	at jc.a(SourceFile:9)
	at ef.a(SourceFile:164)

---- Minecraft Crash Report ----
// You're mean.

Time: 10/26/13 3:31 PM
Description: Ticking memory connection

java.lang.ClassCastException: ano cannot be cast to ani
	at aij.m(SourceFile:250)
	at aij.a(SourceFile:240)
	at mn.a(SourceFile:241)
	at mx.a(SourceFile:365)
	at jc.a(SourceFile:60)
	at jc.a(SourceFile:9)
	at ef.a(SourceFile:164)
	at ms.c(SourceFile:134)
	at net.minecraft.server.MinecraftServer.u(SourceFile:529)
	at net.minecraft.server.MinecraftServer.t(SourceFile:441)
	at bsk.t(SourceFile:117)
	at net.minecraft.server.MinecraftServer.run(SourceFile:358)
	at ky.run(SourceFile:617)


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

-- Head --
Stacktrace:
	at aij.m(SourceFile:250)
	at aij.a(SourceFile:240)
	at mn.a(SourceFile:241)
	at mx.a(SourceFile:365)
	at jc.a(SourceFile:60)
	at jc.a(SourceFile:9)
	at ef.a(SourceFile:164)

-- Ticking connection --
Details:
	Connection: ef@21337590
Stacktrace:
	at ms.c(SourceFile:134)
	at net.minecraft.server.MinecraftServer.u(SourceFile:529)
	at net.minecraft.server.MinecraftServer.t(SourceFile:441)
	at bsk.t(SourceFile:117)
	at net.minecraft.server.MinecraftServer.run(SourceFile:358)
	at ky.run(SourceFile:617)

-- System Details --
Details:
	Minecraft Version: 1.7.2
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.7.0_45, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 179056768 bytes (170 MB) / 367525888 bytes (350 MB) up to 954728448 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 6458 (361648 bytes; 0 MB) allocated, 6043 (338408 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 1303 (72968 bytes; 0 MB) allocated, 1162 (65072 bytes; 0 MB) used
	Player Count: 1 / 8; [mm['sjakupovic'/2079, l='1.7', x=7555.38, y=80.00, z=4403.11]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.