---- Minecraft Crash Report ----
// I blame Dinnerbone.

Time: 3/10/13 7:03 PM
Description: Exception in server tick loop

java.lang.SecurityException: SHA1 digest error for yy.class
	at sun.security.util.ManifestEntryVerifier.verify(Unknown Source)
	at java.util.jar.JarVerifier.processEntry(Unknown Source)
	at java.util.jar.JarVerifier.update(Unknown Source)
	at java.util.jar.JarVerifier$VerifierStream.read(Unknown Source)
	at sun.misc.Resource.getBytes(Unknown Source)
	at java.net.URLClassLoader.defineClass(Unknown Source)
	at java.net.URLClassLoader.access$100(Unknown Source)
	at java.net.URLClassLoader$1.run(Unknown Source)
	at java.net.URLClassLoader$1.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at zd.<init>(SourceFile:26)
	at zd.<init>(SourceFile:36)
	at ahs.a(SourceFile:136)
	at net.minecraft.server.MinecraftServer.b(SourceFile:394)
	at bdz.a(SourceFile:54)
	at bdz.c(SourceFile:99)
	at net.minecraft.server.MinecraftServer.run(SourceFile:588)
	at fy.run(SourceFile:849)


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

-- System Details --
Details:
	Minecraft Version: 1.4.7
	Operating System: Windows XP (x86) version 5.1
	Java Version: 1.7.0_09, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 476544320 bytes (454 MB) / 519110656 bytes (495 MB) up to 1037959168 bytes (989 MB)
	JVM Flags: 2 total; -Xms512m -Xmx1024m
	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 / 8; []
	Type: Integrated Server (map_client.txt)
	Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.