Minecraft Error

---- Minecraft Crash Report ----
// Hi. I'm Minecraft, and I'm a crashaholic.

Time: 27.02.13 17:22
Description: Failed to start game

java.lang.NullPointerException
	at java.io.Reader.<init>(Unknown Source)
	at java.io.InputStreamReader.<init>(Unknown Source)
	at bn.a(SourceFile:56)
	at bn.a(SourceFile:91)
	at net.minecraft.client.Minecraft.a(SourceFile:249)
	at asq.a(SourceFile:56)
	at net.minecraft.client.Minecraft.run(SourceFile:515)
	at java.lang.Thread.run(Unknown Source)


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: 1.4.7
	Operating System: Windows 7 (x86) version 6.1
	Java Version: 1.7.0_15, Oracle Corporation
	Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
	Memory: 447466528 bytes (426 MB) / 518979584 bytes (494 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
	LWJGL: 2.4.2
	OpenGL: GeForce GTX 660/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)
	Texture Pack: KDSPhotorealism256v8m.zip
	Profiler Position: N/A (disabled)
	Vec3 Pool Size: ~~ERROR~~ NullPointerException: null