Hopper: java.lang.SecurityException: SHA1 digest error for avg.class

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-299285/

Crash:

java.lang.SecurityException: SHA1 digest error for avg.class
	at sun.security.util.ManifestEntryVerifier.verify(ManifestEntryVerifier.java:198)
	at java.util.jar.JarVerifier.processEntry(JarVerifier.java:212)
	at java.util.jar.JarVerifier.update(JarVerifier.java:199)
	at java.util.jar.JarVerifier$VerifierStream.read(JarVerifier.java:449)
	at sun.misc.Resource.getBytes(Resource.java:108)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:257)
	at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
	at ats.O(SourceFile:386)

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

---- Minecraft Crash Report ----
// Quite honestly, I wouldn't worry myself about that.

Time: 10/10/13 21:32
Description: Initializing game

java.lang.SecurityException: SHA1 digest error for avg.class
	at sun.security.util.ManifestEntryVerifier.verify(ManifestEntryVerifier.java:198)
	at java.util.jar.JarVerifier.processEntry(JarVerifier.java:212)
	at java.util.jar.JarVerifier.update(JarVerifier.java:199)
	at java.util.jar.JarVerifier$VerifierStream.read(JarVerifier.java:449)
	at sun.misc.Resource.getBytes(Resource.java:108)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:257)
	at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
	at ats.O(SourceFile:386)
	at ats.d(SourceFile:599)
	at net.minecraft.client.main.Main.main(SourceFile:101)


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

-- Head --
Stacktrace:
	at sun.security.util.ManifestEntryVerifier.verify(ManifestEntryVerifier.java:198)
	at java.util.jar.JarVerifier.processEntry(JarVerifier.java:212)
	at java.util.jar.JarVerifier.update(JarVerifier.java:199)
	at java.util.jar.JarVerifier$VerifierStream.read(JarVerifier.java:449)
	at sun.misc.Resource.getBytes(Resource.java:108)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:257)
	at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
	at ats.O(SourceFile:386)

-- Initialization --
Details:
Stacktrace:
	at ats.d(SourceFile:599)
	at net.minecraft.client.main.Main.main(SourceFile:101)

-- System Details --
Details:
	Minecraft Version: 1.6.2
	Operating System: Mac OS X (x86_64) version 10.7.5
	Java Version: 1.6.0_51, Apple Inc.
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
	Memory: 55033784 bytes (52 MB) / 85000192 bytes (81 MB) up to 1065025536 bytes (1015 MB)
	JVM Flags: 1 total; -Xmx1G
	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
	Launched Version: minimap
	LWJGL: 2.9.0
	OpenGL: AMD Radeon HD 6750M OpenGL Engine GL version 2.1 ATI-7.32.12, ATI Technologies Inc.
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Pack: Default
	Current Language: Français (France)
	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-299285/16605410/