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

Time: 21/04/13 21:01
Description: Exception in server tick loop

java.lang.RuntimeException: Failed to check session lock, aborting
	at ajt.h(SourceFile:45)
	at ajt.<init>(SourceFile:31)
	at ajp.<init>(SourceFile:16)
	at ajq.a(SourceFile:83)
	at net.minecraft.server.MinecraftServer.a(SourceFile:152)
	at hz.c(SourceFile:176)
	at net.minecraft.server.MinecraftServer.run(SourceFile:306)
	at gp.run(SourceFile:573)


A detailed walkthrough of the error, its code path and all known details is as follows:
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-- System Details --
Details:
	Minecraft Version: 1.5.1
	Operating System: Linux (amd64) version 3.2.13-grsec-xxxx-grs-ipv6-64
	Java Version: 1.7.0, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 991455496 bytes (945 MB) / 1029046272 bytes (981 MB) up to 1029046272 bytes (981 MB)
	JVM Flags: 2 total; -Xmx1024M -Xms1024M
	AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
	Suspicious classes: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Profiler Position: N/A (disabled)
	Player Count: 0 / 20; []
	Is Modded: Unknown (can't tell)
	Type: Dedicated Server (map_server.txt)