Game Crash?

I have no Idea what happened, I'm using 13w38c and I just crashed. Here is the crash report.

---- Minecraft Crash Report ----
    // Oops.
     
    Time: 9/25/13 4:50 PM
    Description: Rendering entity in world
     
    java.lang.NullPointerException
            at biw.a(SourceFile:74)
            at bjt.a(SourceFile:53)
            at bjt.a(SourceFile:16)
            at bjq.a(SourceFile:215)
            at bjq.a(SourceFile:196)
            at bmt.a(SourceFile:30)
            at bmt.a(SourceFile:15)
            at bmt.a(SourceFile:10)
            at bmy.a(SourceFile:100)
            at bmy.a(SourceFile:92)
            at bip.a(SourceFile:354)
            at bii.a(SourceFile:974)
            at bii.b(SourceFile:809)
            at awp.aa(SourceFile:754)
            at awp.e(SourceFile:677)
            at net.minecraft.client.main.Main.main(SourceFile:104)
     
     
    A detailed walkthrough of the error, its code path and all known details is as follows:
    ---------------------------------------------------------------------------------------
     
    -- Head --
    Stacktrace:
            at biw.a(SourceFile:74)
            at bjt.a(SourceFile:53)
            at bjt.a(SourceFile:16)
     
    -- Entity being rendered --
    Details:
            Entity Type: FallingSand (ts)
            Entity ID: 435602
            Entity Name: Falling Block
            Entity's Exact location: -61.10, 19.38, 4.45
            Entity's Block location: World: (-62,19,4), Chunk: (at 2,1,4 in -4,0; contains blocks -64,0,0 to -49,255,15), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
            Entity's Momentum: 0.00, 0.00, 0.00
            Immitating block ID: -1
            Immitating block data: 0
     
    -- Renderer details --
    Details:
            Assigned renderer: bjt@480b0222
            Location: 0.00,0.00,0.00 - World: (0,0,0), Chunk: (at 0,0,0 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)
            Rotation: 0.0
            Delta: 0.30704308
    Stacktrace:
            at bjq.a(SourceFile:215)
            at bjq.a(SourceFile:196)
            at bmt.a(SourceFile:30)
            at bmt.a(SourceFile:15)
            at bmt.a(SourceFile:10)
     
    -- Tile Entity Details --
    Details:
            Name: MobSpawner // avd
            Block type: ID #52 (tile.mobSpawner // asa)
            Block data value: 0 / 0x0 / 0b0000
            Block location: World: (-12,145,-19), Chunk: (at 4,9,13 in -1,-2; contains blocks -16,0,-32 to -1,255,-17), Region: (-1,-1; contains chunks -32,-32 to -1,-1, blocks -512,0,-512 to -1,255,-1)
            Actual block type: ID #52 (tile.mobSpawner // asa)
            Actual block data value: 0 / 0x0 / 0b0000
    Stacktrace:
            at bmy.a(SourceFile:100)
            at bmy.a(SourceFile:92)
            at bip.a(SourceFile:354)
            at bii.a(SourceFile:974)
     
    -- Affected level --
    Details:
            Level name: MpServer
            All players: 2 total; [bgh['SkyKiller63'/270431, l='MpServer', x=48.93, y=125.62, z=-23.38], bic['ShadyB72'/273289, l='MpServer', x=89.98, y=124.00, z=-22.72]]
            Chunk stats: MultiplayerChunkCache: 347, 347
            Level seed: 0
            Level generator: ID 01 - flat, ver 0. Features enabled: false
            Level generator options:
            Level spawn location: World: (-46,150,100), Chunk: (at 2,9,4 in -3,6; contains blocks -48,0,96 to -33,255,111), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
            Level time: 7961614 game time, 119612 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: survival (ID 0). Hardcore: false. Cheats: false
            Forced entities: 123 total; [sn['Bat'/427318, l='MpServer', x=57.72, y=34.00, z=-74.59], sn['Bat'/427317, l='MpServer', x=63.53, y=34.21, z=-83.03], ug['Creeper'/431108, l='MpServer', x=34.50, y=51.00, z=-65.50], ug['Creeper'/431926, l='MpServer', x=-12.50, y=185.00, z=-66.50], ug['Creeper'/431927, l='MpServer', x=-14.00, y=185.00, z=-64.50], pc['entity.ItemFrame.name'/270336, l='MpServer', x=90.06, y=125.50, z=-32.50], pc['entity.ItemFrame.name'/270337, l='MpServer', x=89.50, y=125.50, z=-31.94], vi['arrow'/270350, l='MpServer', x=81.78, y=156.94, z=18.59], vi['arrow'/270351, l='MpServer', x=82.03, y=156.44, z=18.50], uu['Spider'/431933, l='MpServer', x=79.50, y=94.00, z=-77.50], us['Skeleton'/431664, l='MpServer', x=-6.50, y=185.00, z=-59.50], uu['Spider'/428739, l='MpServer', x=83.09, y=25.00, z=43.50], ux['Zombie'/433827, l='MpServer', x=63.44, y=129.00, z=18.88], bic['ShadyB72'/273289, l='MpServer', x=89.98, y=124.00, z=-22.72], ux['Zombie'/430661, l='MpServer', x=53.09, y=51.00, z=-75.38], uu['Spider'/429446, l='MpServer', x=-14.97, y=94.00, z=-11.34], ux['Zombie'/430658, l='MpServer', x=39.50, y=51.00, z=-69.50], sn['Bat'/435279, l='MpServer', x=32.01, y=52.35, z=-78.95], sn['Bat'/435280, l='MpServer', x=39.23, y=51.00, z=-76.14], sn['Bat'/435282, l='MpServer', x=45.11, y=51.00, z=-63.46], sn['Bat'/435284, l='MpServer', x=37.04, y=52.77, z=-59.81], uu['Spider'/434197, l='MpServer', x=87.13, y=68.00, z=-71.03], bic['ShadyB72'/273289, l='MpServer', x=89.98, y=124.00, z=-22.72], ux['Zombie'/429728, l='MpServer', x=-19.50, y=135.00, z=4.50], uu['Spider'/434198, l='MpServer', x=90.41, y=68.00, z=-70.28], uu['Spider'/434195, l='MpServer', x=87.50, y=68.00, z=-73.94], uu['Spider'/434194, l='MpServer', x=88.63, y=68.00, z=-69.00], uh['Enderman'/433908, l='MpServer', x=117.63, y=75.00, z=22.50], ux['Zombie'/432521, l='MpServer', x=-1.75, y=94.00, z=-27.25], pc['entity.ItemFrame.name'/270412, l='MpServer', x=100.94, y=103.50, z=96.50], ux['Zombie'/432523, l='MpServer', x=-6.66, y=94.00, z=-26.66], pc['entity.ItemFrame.name'/326003, l='MpServer', x=53.94, y=44.50, z=-129.50], uh['Enderman'/435477, l='MpServer', x=78.59, y=142.00, z=-69.38], uu['Spider'/435475, l='MpServer', x=80.50, y=142.00, z=-62.50], uu['Spider'/435474, l='MpServer', x=77.65, y=142.00, z=-63.96], uu['Spider'/435473, l='MpServer', x=80.50, y=142.00, z=-66.50], us['Skeleton'/419922, l='MpServer', x=71.50, y=31.00, z=39.50], bgh['SkyKiller63'/270431, l='MpServer', x=48.93, y=125.62, z=-23.38], ug['Creeper'/430048, l='MpServer', x=104.50, y=79.00, z=-5.50], ux['Zombie'/434506, l='MpServer', x=34.34, y=61.00, z=-90.91], ux['Zombie'/434505, l='MpServer', x=31.75, y=61.00, z=-98.63], ug['Creeper'/430136, l='MpServer', x=75.28, y=68.00, z=-64.88], sn['Bat'/414360, l='MpServer', x=62.28, y=52.10, z=3.69], ux['Zombie'/434498, l='MpServer', x=35.50, y=72.00, z=-73.50], sn['Bat'/430849, l='MpServer', x=34.34, y=51.85, z=-58.16], ux['Zombie'/434499, l='MpServer', x=30.13, y=61.00, z=-96.72], uu['Spider'/430135, l='MpServer', x=73.28, y=68.00, z=-76.66], ux['Zombie'/434501, l='MpServer', x=31.50, y=61.00, z=-94.50], us['Skeleton'/433421, l='MpServer', x=68.50, y=70.00, z=19.50], us['Skeleton'/432211, l='MpServer', x=85.50, y=40.00, z=11.50], pc['entity.ItemFrame.name'/416922, l='MpServer', x=48.06, y=43.50, z=-125.50], pc['entity.ItemFrame.name'/416921, l='MpServer', x=53.94, y=42.50, z=-126.50], us['Skeleton'/430286, l='MpServer', x=46.50, y=34.00, z=-90.50], us['Skeleton'/430287, l='MpServer', x=47.50, y=34.00, z=-93.50], ux['Zombie'/434359, l='MpServer', x=19.13, y=179.00, z=-31.41], uu['Spider'/433155, l='MpServer', x=70.50, y=92.00, z=-90.50], us['Skeleton'/432207, l='MpServer', x=84.50, y=40.00, z=4.50], ux['Zombie'/433153, l='MpServer', x=-14.50, y=126.00, z=-15.50], ux['Zombie'/434362, l='MpServer', x=15.97, y=179.00, z=-29.28], us['Skeleton'/431796, l='MpServer', x=43.50, y=81.00, z=18.50], ux['Zombie'/434360, l='MpServer', x=13.50, y=179.00, z=-30.50], ux['Zombie'/434361, l='MpServer', x=14.50, y=179.00, z=-31.50], uu['Spider'/435127, l='MpServer', x=85.63, y=68.00, z=-55.78], uu['Spider'/435128, l='MpServer', x=85.50, y=68.00, z=-57.50], uu['Spider'/435129, l='MpServer', x=85.19, y=68.00, z=-59.28], sn['Bat'/422687, l='MpServer', x=63.97, y=34.17, z=-74.56], us['Skeleton'/435395, l='MpServer', x=66.50, y=126.00, z=19.50], uu['Spider'/435130, l='MpServer', x=95.47, y=68.00, z=-57.21], ux['Zombie'/435418, l='MpServer', x=98.50, y=40.00, z=14.50], ux['Zombie'/435419, l='MpServer', x=96.50, y=40.00, z=9.50], uu['Spider'/431047, l='MpServer', x=75.06, y=68.00, z=-61.00], ug['Creeper'/435113, l='MpServer', x=24.53, y=62.00, z=-104.00], ug['Creeper'/432499, l='MpServer', x=26.06, y=125.00, z=-49.50], us['Skeleton'/433193, l='MpServer', x=77.63, y=142.00, z=-70.38], us['Skeleton'/433192, l='MpServer', x=77.50, y=142.00, z=-65.69], uu['Spider'/435414, l='MpServer', x=95.48, y=40.00, z=14.12], us['Skeleton'/433195, l='MpServer', x=82.50, y=142.00, z=-64.50], ug['Creeper'/435118, l='MpServer', x=-23.50, y=128.00, z=13.50], uu['Spider'/435415, l='MpServer', x=99.50, y=40.00, z=12.50], us['Skeleton'/433194, l='MpServer', x=78.69, y=142.00, z=-65.69], us['Skeleton'/431854, l='MpServer', x=4.50, y=129.00, z=-15.50], ux['Zombie'/428569, l='MpServer', x=63.50, y=34.00, z=-77.50], sn['Bat'/434018, l='MpServer', x=38.63, y=51.00, z=-62.00], sn['Bat'/434017, l='MpServer', x=50.16, y=51.02, z=-67.59], sn['Bat'/432689, l='MpServer', x=52.03, y=51.65, z=-63.66], us['Skeleton'/427232, l='MpServer', x=67.91, y=68.00, z=25.63], sn['Bat'/432690, l='MpServer', x=49.03, y=51.09, z=-60.31], ux['Zombie'/428566, l='MpServer', x=63.50, y=34.00, z=-69.50], sn['Bat'/432695, l='MpServer', x=58.63, y=52.71, z=-67.28], sn['Bat'/431322, l='MpServer', x=116.60, y=40.00, z=13.80], ug['Creeper'/429905, l='MpServer', x=75.50, y=122.00, z=24.50], us['Skeleton'/434420, l='MpServer', x=66.50, y=94.00, z=-75.50], sn['Bat'/432687, l='MpServer', x=43.50, y=52.27, z=-71.78], oz['Experience Orb'/421517, l='MpServer', x=97.16, y=82.75, z=-5.25], oz['Experience Orb'/421516, l='MpServer', x=96.00, y=80.75, z=-1.94], ux['Zombie'/433499, l='MpServer', x=-11.50, y=94.00, z=-25.50], ux['Zombie'/433500, l='MpServer', x=-15.34, y=94.00, z=-27.69], uu['Spider'/433501, l='MpServer', x=-13.50, y=94.00, z=-21.50], uu['Spider'/433502, l='MpServer', x=-17.34, y=94.00, z=-27.34], sn['Bat'/429138, l='MpServer', x=72.59, y=50.77, z=1.34], tt['item.tile.dirt.default'/418826, l='MpServer', x=91.81, y=66.13, z=23.75], tt['item.tile.stonebricksmooth.default'/418827, l='MpServer', x=92.72, y=67.13, z=23.31], tt['item.tile.dirt.default'/418828, l='MpServer', x=89.16, y=67.13, z=24.81], tt['item.tile.dirt.default'/418829, l='MpServer', x=92.91, y=67.13, z=23.22], tt['item.tile.dirt.default'/418830, l='MpServer', x=90.00, y=67.13, z=23.97], tt['item.tile.dirt.default'/418831, l='MpServer', x=90.88, y=67.13, z=24.84], ug['Creeper'/434927, l='MpServer', x=-19.50, y=121.00, z=3.50], us['Skeleton'/431606, l='MpServer', x=90.50, y=72.00, z=18.50], ux['Zombie'/433278, l='MpServer', x=-30.50, y=127.00, z=-45.50], ux['Zombie'/432920, l='MpServer', x=76.50, y=142.00, z=-74.50], ux['Zombie'/432921, l='MpServer', x=77.31, y=142.00, z=-78.13], ug['Creeper'/434928, l='MpServer', x=-20.50, y=121.00, z=3.50], ug['Creeper'/434929, l='MpServer', x=-18.50, y=121.00, z=5.50], ux['Zombie'/432913, l='MpServer', x=-23.50, y=135.00, z=6.50], sn['Bat'/434013, l='MpServer', x=29.25, y=51.73, z=-57.38], tt['item.tile.dirt.default'/418832, l='MpServer', x=91.16, y=66.13, z=23.44], ux['Zombie'/432915, l='MpServer', x=-22.50, y=135.00, z=13.50], sn['Bat'/434015, l='MpServer', x=58.16, y=51.95, z=-61.53], ux['Zombie'/432916, l='MpServer', x=-22.97, y=137.00, z=14.50], ux['Zombie'/432917, l='MpServer', x=-17.50, y=135.00, z=6.50], sn['Bat'/429135, l='MpServer', x=79.78, y=51.12, z=7.88], ux['Zombie'/432918, l='MpServer', x=76.50, y=142.00, z=-75.50], ux['Zombie'/432919, l='MpServer', x=72.59, y=142.00, z=-82.09]]
            Retry entities: 0 total; []
            Server brand: vanilla
            Server type: Integrated singleplayer server
    Stacktrace:
            at bgc.a(SourceFile:297)
            at awp.b(SourceFile:1874)
            at awp.e(SourceFile:686)
            at net.minecraft.client.main.Main.main(SourceFile:104)
     
    -- System Details --
    Details:
            Minecraft Version: 13w38c
            Operating System: Mac OS X (x86_64) version 10.8.4
            Java Version: 1.6.0_45, Apple Inc.
            Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Apple Inc.
            Memory: 229948272 bytes (219 MB) / 448946176 bytes (428 MB) up to 2143158272 bytes (2043 MB)
            JVM Flags: 1 total; -Xmx2G
            AABB Pool Size: 1742 (97552 bytes; 0 MB) allocated, 1678 (93968 bytes; 0 MB) used
            IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
            Launched Version: 13w38c
            LWJGL: 2.9.0
            OpenGL: NVIDIA GeForce 9400M OpenGL Engine GL version 2.1 NVIDIA-8.12.47 310.40.00.05f01, NVIDIA Corporation
            Is Modded: Probably not. Jar signature remains and client brand is untouched.
            Type: Client (map_client.txt)
            Resource Packs: [SkyKiller63, Sound Pack]
            Current Language: English (US)
            Profiler Position: N/A (disabled)
            Vec3 Pool Size: 1314 (73584 bytes; 0 MB) allocated, 252 (14112 bytes; 0 MB) used