Hopper: java.lang.ClassCastException: amh cannot be cast to ahq

java.lang.ClassCastException: amh cannot be cast to ahq
	at ahr.<init>(SourceFile:33)
	at ahq.a(SourceFile:372)
	at ahq.b(SourceFile:334)
	at aoj.a(SourceFile:468)
	at afn.d(SourceFile:327)
	at atv.a(SourceFile:411)
	at atv.a(SourceFile:535)
	at ark.a(SourceFile:447)
	at atx.a(SourceFile:37)
	at atp.a(SourceFile:88)
	at apl.a(SourceFile:403)
	at mi.a(SourceFile:160)
	at aoj.a(SourceFile:781)
	at mi.c(SourceFile:95)
	at mh.<init>(SourceFile:31)
	at mg.a(SourceFile:212)
	at mg.d(SourceFile:346)
	at ld.d(SourceFile:215)
	at mx.a(SourceFile:280)
	at ir.a(SourceFile:137)
	at is.a(SourceFile:63)
	at ef.a(SourceFile:164)

---- Minecraft Crash Report ----
// Don't be sad, have a hug! <3

Time: 10/25/13 12:00 PM
Description: Ticking memory connection

java.lang.ClassCastException: amh cannot be cast to ahq
	at ahr.<init>(SourceFile:33)
	at ahq.a(SourceFile:372)
	at ahq.b(SourceFile:334)
	at aoj.a(SourceFile:468)
	at afn.d(SourceFile:327)
	at atv.a(SourceFile:411)
	at atv.a(SourceFile:535)
	at ark.a(SourceFile:447)
	at atx.a(SourceFile:37)
	at atp.a(SourceFile:88)
	at apl.a(SourceFile:403)
	at mi.a(SourceFile:160)
	at aoj.a(SourceFile:781)
	at mi.c(SourceFile:95)
	at mh.<init>(SourceFile:31)
	at mg.a(SourceFile:212)
	at mg.d(SourceFile:346)
	at ld.d(SourceFile:215)
	at mx.a(SourceFile:280)
	at ir.a(SourceFile:137)
	at is.a(SourceFile:63)
	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 ahr.<init>(SourceFile:33)
	at ahq.a(SourceFile:372)
	at ahq.b(SourceFile:334)
	at aoj.a(SourceFile:468)
	at afn.d(SourceFile:327)
	at atv.a(SourceFile:411)
	at atv.a(SourceFile:535)
	at ark.a(SourceFile:447)
	at atx.a(SourceFile:37)
	at atp.a(SourceFile:88)
	at apl.a(SourceFile:403)
	at mi.a(SourceFile:160)
	at aoj.a(SourceFile:781)
	at mi.c(SourceFile:95)
	at mh.<init>(SourceFile:31)
	at mg.a(SourceFile:212)
	at mg.d(SourceFile:346)
	at ld.d(SourceFile:215)
	at mx.a(SourceFile:280)
	at ir.a(SourceFile:137)
	at is.a(SourceFile:63)
	at ef.a(SourceFile:164)

-- Ticking connection --
Details:
	Connection: ef@7ceed95b
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_13, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 205988040 bytes (196 MB) / 347865088 bytes (331 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 4265 (238840 bytes; 0 MB) allocated, 3084 (172704 bytes; 0 MB) used
	IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: 1427 (79912 bytes; 0 MB) allocated, 1271 (71176 bytes; 0 MB) used
	Player Count: 1 / 8; [mm['db22'/116, l='Creative', x=1952.33, y=82.61, z=-1185.42]]
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.