Hopper: java.lang.RuntimeException: Failed to check session lock, aborting

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-73025/

Crash:

java.lang.RuntimeException: Failed to check session lock, aborting
	at ann.h(SourceFile:44)
	at ann.<init>(SourceFile:30)
	at anj.<init>(SourceFile:16)
	at ank.a(SourceFile:68)
	at avx.a(SourceFile:1463)
	at axu.a(SourceFile:202)
	at ayr.a(SourceFile:70)
	at axu.a(SourceFile:301)
	at ayr.d(SourceFile:133)
	at ayr.m(SourceFile:109)

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

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

Time: 9/5/13 10:58 AM
Description: Updating screen events

java.lang.RuntimeException: Failed to check session lock, aborting
	at ann.h(SourceFile:44)
	at ann.<init>(SourceFile:30)
	at anj.<init>(SourceFile:16)
	at ank.a(SourceFile:68)
	at avx.a(SourceFile:1463)
	at axu.a(SourceFile:202)
	at ayr.a(SourceFile:70)
	at axu.a(SourceFile:301)
	at ayr.d(SourceFile:133)
	at ayr.m(SourceFile:109)
	at avx.m(SourceFile:1202)
	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:
---------------------------------------------------------------------------------------

-- Head --
Stacktrace:
	at ann.h(SourceFile:44)
	at ann.<init>(SourceFile:30)
	at anj.<init>(SourceFile:16)
	at ank.a(SourceFile:68)
	at avx.a(SourceFile:1463)
	at axu.a(SourceFile:202)
	at ayr.a(SourceFile:70)
	at axu.a(SourceFile:301)
	at ayr.d(SourceFile:133)
	at ayr.m(SourceFile:109)

-- Affected screen --
Details:
	Screen name: bny
Stacktrace:
	at avx.m(SourceFile:1202)
	at avx.V(SourceFile:686)
	at avx.e(SourceFile:642)
	at net.minecraft.client.main.Main.main(SourceFile:103)

-- System Details --
Details:
	Minecraft Version: 13w36a
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.6.0_27, Sun Microsystems Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Sun Microsystems Inc.
	Memory: 166767128 bytes (159 MB) / 196476928 bytes (187 MB) up to 954466304 bytes (910 MB)
	JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
	AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 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: 0, tallocated: 0
	Launched Version: 13w36a
	LWJGL: 2.9.0
	OpenGL: Intel(R) HD Graphics Family GL version 3.0.0 - Build 8.15.10.2291, Intel
	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: ~~ERROR~~ NullPointerException: null

You can see this full report at http://hopper.minecraft.net/crashes/minecraft/MCX-73025/8100130/