I started a world and it crashed right when it got on. Here is the report:

---- Minecraft Crash Report ----
// Ouch. That hurt

Time: 2/28/14 1:50 PM
Description: Getting biome

java.lang.NullPointerException: Getting biome
at aou.a(SourceFile:934)
at afy.a(SourceFile:114)
at afy.a(SourceFile:1045)
at bms.j(SourceFile:1343)
at bms.a(SourceFile:928)
at bms.b(SourceFile:814)
at azl.ah(SourceFile:784)
at azl.f(SourceFile:711)
at net.minecraft.client.main.Main.main(SourceFile:148)

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

– Head –
Stacktrace:
at aou.a(SourceFile:934)

– Coordinates of biome request –
Details:
Location: World: (8,0,8), Chunk: (at 8,0,8 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Stacktrace:
at afy.a(SourceFile:114)
at afy.a(SourceFile:1045)
at bms.j(SourceFile:1343)
at bms.a(SourceFile:928)

– Affected level –
Details:
Level name: MpServer
All players: 1 total; [bkl['alal132'/73644, l='MpServer', x=8.50, y=66.62, z=8.50]]
Chunk stats: MultiplayerChunkCache: 0, 0
Level seed: 0
Level generator: ID 00 - default, ver 1. Features enabled: false
Level generator options:
Level spawn location: World: (180,64,228), Chunk: (at 4,4,4 in 11,14; contains blocks 176,0,224 to 191,255,239), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 0 game time, 0 day time
Level dimension: 0
Level storage version: 0x00000 - Unknown?
Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
Level game mode: Game mode: creative (ID 1). Hardcore: false. Cheats: false
Forced entities: 1 total; [bkl['alal132'/73644, l='MpServer', x=8.50, y=66.62, z=8.50]]
Retry entities: 0 total; []
Server brand: vanilla
Server type: Integrated singleplayer server
Stacktrace:
at bkg.a(SourceFile:289)
at azl.b(SourceFile:1947)
at azl.f(SourceFile:720)
at net.minecraft.client.main.Main.main(SourceFile:148)

– System Details –
Details:
Minecraft Version: 1.7.5
Operating System: Windows 8 (amd64) version 6.2
Java Version: 1.7.0_45, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 336263016 bytes (320 MB) / 457179136 bytes (436 MB) up to 954728448 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
IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 113
Launched Version: 1.7.5
LWJGL: 2.9.1
OpenGL: Intel(R) HD Graphics 4000 GL version 4.0.0 - Build 10.18.10.3379, Intel
GL Caps: Using GL 1.3 multitexturing.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Anisotropic filtering is supported and maximum anisotropy is 16.
Shaders are available because OpenGL 2.1 is supported.

Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs: []
Current Language: English (UK)
Profiler Position: N/A (disabled)
Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Anisotropic Filtering: Off (1)