Hopper: java.lang.ArithmeticException: / by zero

This is an automatically generated report based from the following crash: http://hopper.minecraft.net/crashes/minecraft/MCX-192249/

Crash:

java.lang.ArithmeticException: / by zero
	at bfe.b(SourceFile:685)
	at atv.S(SourceFile:686)
	at atv.d(SourceFile:619)
	at net.minecraft.client.main.Main.main(SourceFile:101)

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

---- Minecraft Crash Report ----
// Why is it breaking :(

Time: 9/19/13 4:46 PM
Description: Unexpected error

java.lang.ArithmeticException: / by zero
	at bfe.b(SourceFile:685)
	at atv.S(SourceFile:686)
	at atv.d(SourceFile:619)
	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:
---------------------------------------------------------------------------------------

-- System Details --
Details:
	Minecraft Version: 1.6.4
	Operating System: Windows 8 (amd64) version 6.2
	Java Version: 1.7.0_21, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 80925120 bytes (77 MB) / 139788288 bytes (133 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: No suspicious classes found.
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 1.6.4
	LWJGL: 2.9.0
	OpenGL: GeForce GT 650M/PCIe/SSE2 GL version 4.2.0, NVIDIA Corporation
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Pack: Default
	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-192249/12436343/