IndexOutOfBoundsException whilst playing on single-player.

What I expected to happen was...:
No errors.

What actually happened was...:
Game crashed, with the following error details:

---- Minecraft Crash Report ----
// I blame Dinnerbone.

Time: 27/12/13 12:02 AM
Description: Updating screen events

java.lang.IndexOutOfBoundsException: Index: 48, Size: 45
at java.util.ArrayList.rangeCheck(Unknown Source)
at java.util.ArrayList.get(Unknown Source)
at ye.a(SourceFile:281)
at biy.a(SourceFile:308)
at bdd.a(SourceFile:490)
at bdd.a(SourceFile:514)
at bdd.a(SourceFile:499)
at bcd.l(SourceFile:258)
at bcd.k(SourceFile:217)
at azd.o(SourceFile:1303)
at azd.ad(SourceFile:753)
at azd.e(SourceFile:704)
at net.minecraft.client.main.Main.main(SourceFile:103)

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

– Head –
Stacktrace:
at java.util.ArrayList.rangeCheck(Unknown Source)
at java.util.ArrayList.get(Unknown Source)
at ye.a(SourceFile:281)
at biy.a(SourceFile:308)
at bdd.a(SourceFile:490)
at bdd.a(SourceFile:514)
at bdd.a(SourceFile:499)
at bcd.l(SourceFile:258)
at bcd.k(SourceFile:217)

– Affected screen –
Details:
Screen name: ~_ERROR~ NullPointerException: null

– Affected level –
Details:
Level name: MpServer
All players: 1 total; [bje['leiger'/219, l='MpServer', x=668.48, y=73.62, z=448.40]]
Chunk stats: MultiplayerChunkCache: 340, 340
Level seed: 0
Level generator: ID 00 - default, ver 1. Features enabled: false
Level generator options:
Level spawn location: World: (674,64,434), Chunk: (at 2,4,2 in 42,27; contains blocks 672,0,432 to 687,255,447), Region: (1,0; contains chunks 32,0 to 63,31, blocks 512,0,0 to 1023,255,511)
Level time: 67698 game time, 72806 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: 97 total; [wx['Skeleton'/60679, l='MpServer', x=736.50, y=45.00, z=497.50], wz['Spider'/62900, l='MpServer', x=683.50, y=39.00, z=517.50], ve['Squid'/62425, l='MpServer', x=608.25, y=49.06, z=420.50], wx['Skeleton'/58526, l='MpServer', x=655.50, y=47.00, z=462.03], xb['Witch'/62895, l='MpServer', x=612.50, y=34.00, z=392.50], wx['Skeleton'/62892, l='MpServer', x=612.50, y=34.00, z=390.50], vb['Sheep'/19, l='MpServer', x=620.72, y=74.00, z=509.69], wx['Skeleton'/62893, l='MpServer', x=609.50, y=34.00, z=395.50], vb['Sheep'/18, l='MpServer', x=616.66, y=72.00, z=508.19], vb['Sheep'/20, l='MpServer', x=619.31, y=76.00, z=503.84], vw['item.item.egg'/61687, l='MpServer', x=653.13, y=70.13, z=484.94], vb['Sheep'/22, l='MpServer', x=606.03, y=62.07, z=446.97], vb['Sheep'/25, l='MpServer', x=630.53, y=66.00, z=460.47], vb['Sheep'/24, l='MpServer', x=631.50, y=69.00, z=477.81], vb['Sheep'/26, l='MpServer', x=621.31, y=63.00, z=449.72], vb['Sheep'/28, l='MpServer', x=620.44, y=72.00, z=513.94], wl['Creeper'/62877, l='MpServer', x=735.50, y=26.00, z=515.50], vb['Sheep'/35, l='MpServer', x=656.56, y=63.00, z=407.13], wl['Creeper'/62878, l='MpServer', x=736.50, y=26.00, z=514.50], us['Chicken'/39, l='MpServer', x=654.44, y=70.00, z=485.53], wl['Creeper'/62601, l='MpServer', x=690.06, y=31.00, z=487.50], vb['Sheep'/37, l='MpServer', x=626.13, y=63.00, z=462.59], wm['Enderman'/62598, l='MpServer', x=693.72, y=31.00, z=480.69], xb['Witch'/62463, l='MpServer', x=697.50, y=32.00, z=491.50], wl['Creeper'/62599, l='MpServer', x=692.97, y=29.00, z=474.38], wm['Enderman'/62597, l='MpServer', x=690.03, y=31.00, z=489.53], wx['Skeleton'/62460, l='MpServer', x=721.50, y=32.00, z=526.50], vb['Sheep'/47, l='MpServer', x=667.91, y=63.00, z=409.06], wl['Creeper'/62592, l='MpServer', x=717.50, y=27.00, z=514.50], wz['Spider'/60253, l='MpServer', x=687.88, y=70.00, z=453.91], wx['Skeleton'/62439, l='MpServer', x=743.41, y=44.00, z=517.97], wy['Slime'/52594, l='MpServer', x=713.69, y=18.00, z=523.31], wl['Creeper'/60249, l='MpServer', x=707.66, y=69.00, z=460.50], vb['Sheep'/54, l='MpServer', x=669.13, y=75.00, z=505.50], vb['Sheep'/53, l='MpServer', x=661.50, y=70.00, z=468.50], vy['entity.MinecartChest.name'/59, l='MpServer', x=660.50, y=32.50, z=499.50], vb['Sheep'/58, l='MpServer', x=666.13, y=71.00, z=476.09], vb['Sheep'/56, l='MpServer', x=662.94, y=69.00, z=491.03], xc['Zombie'/61663, l='MpServer', x=672.50, y=43.00, z=511.50], vb['Sheep'/61, l='MpServer', x=681.38, y=69.00, z=496.75], vb['Sheep'/60, l='MpServer', x=657.59, y=70.00, z=496.78], vb['Sheep'/68, l='MpServer', x=693.63, y=69.00, z=494.47], vy['entity.MinecartChest.name'/69, l='MpServer', x=678.50, y=24.50, z=502.50], wx['Skeleton'/61047, l='MpServer', x=674.50, y=53.00, z=507.50], vb['Sheep'/70, l='MpServer', x=679.97, y=69.00, z=497.06], vb['Sheep'/64, l='MpServer', x=691.13, y=68.00, z=408.13], vb['Sheep'/67, l='MpServer', x=659.94, y=70.00, z=485.97], vb['Sheep'/77, l='MpServer', x=685.81, y=66.00, z=525.66], wl['Creeper'/53041, l='MpServer', x=698.66, y=56.00, z=472.13], vb['Sheep'/93, l='MpServer', x=696.50, y=70.00, z=524.66], vb['Sheep'/92, l='MpServer', x=688.66, y=76.00, z=521.53], uq['Bat'/62111, l='MpServer', x=691.69, y=28.10, z=467.56], uq['Bat'/62110, l='MpServer', x=678.55, y=23.43, z=462.77], wl['Creeper'/59693, l='MpServer', x=596.50, y=38.00, z=385.50], vb['Sheep'/98, l='MpServer', x=706.19, y=69.00, z=426.19], vb['Sheep'/99, l='MpServer', x=708.13, y=69.00, z=428.09], wl['Creeper'/60174, l='MpServer', x=724.50, y=68.00, z=460.50], xc['Zombie'/62920, l='MpServer', x=743.50, y=28.00, z=383.50], vb['Sheep'/119, l='MpServer', x=724.34, y=71.00, z=522.22], wl['Creeper'/61588, l='MpServer', x=602.53, y=34.00, z=407.03], xc['Zombie'/62916, l='MpServer', x=672.37, y=25.00, z=508.23], wl['Creeper'/62919, l='MpServer', x=741.50, y=28.00, z=379.50], vb['Sheep'/129, l='MpServer', x=734.09, y=68.00, z=472.16], vb['Sheep'/128, l='MpServer', x=734.88, y=67.00, z=467.94], vb['Sheep'/131, l='MpServer', x=736.88, y=67.00, z=472.03], vb['Sheep'/130, l='MpServer', x=732.97, y=68.00, z=470.94], wx['Skeleton'/60392, l='MpServer', x=741.50, y=27.00, z=526.50], uq['Bat'/61348, l='MpServer', x=728.33, y=27.67, z=516.43], uq['Bat'/62767, l='MpServer', x=683.50, y=41.98, z=519.25], uq['Bat'/60413, l='MpServer', x=686.75, y=34.10, z=497.38], wx['Skeleton'/62063, l='MpServer', x=670.50, y=44.00, z=511.50], wx['Skeleton'/60601, l='MpServer', x=718.50, y=23.00, z=504.50], xb['Witch'/62465, l='MpServer', x=695.31, y=32.83, z=496.00], wl['Creeper'/60113, l='MpServer', x=613.50, y=67.00, z=496.50], vw['item.item.rottenFlesh'/62078, l='MpServer', x=623.22, y=67.13, z=485.94], vw['item.item.rottenFlesh'/62073, l='MpServer', x=665.31, y=69.13, z=437.81], xc['Zombie'/62064, l='MpServer', x=670.50, y=44.00, z=512.50], rc['Experience Orb'/59900, l='MpServer', x=677.84, y=71.25, z=459.38], xc['Zombie'/60379, l='MpServer', x=684.88, y=33.00, z=524.56], wl['Creeper'/58705, l='MpServer', x=647.50, y=8.00, z=433.50], wl['Creeper'/60632, l='MpServer', x=637.50, y=76.00, z=492.50], uq['Bat'/62567, l='MpServer', x=674.00, y=28.73, z=455.45], bje['leiger'/219, l='MpServer', x=668.48, y=73.62, z=448.40], wz['Spider'/62818, l='MpServer', x=668.28, y=22.00, z=517.66], uq['Bat'/62590, l='MpServer', x=749.13, y=38.00, z=501.47], uq['Bat'/62802, l='MpServer', x=726.33, y=26.52, z=528.49], wl['Creeper'/53592, l='MpServer', x=694.56, y=58.00, z=472.69], wx['Skeleton'/60904, l='MpServer', x=671.50, y=26.00, z=522.50], wl['Creeper'/53593, l='MpServer', x=686.56, y=63.00, z=463.97], uq['Bat'/62804, l='MpServer', x=714.52, y=33.67, z=528.16], xc['Zombie'/60911, l='MpServer', x=690.31, y=62.00, z=463.78], xc['Zombie'/60910, l='MpServer', x=696.31, y=57.00, z=472.28], wy['Slime'/54547, l='MpServer', x=692.31, y=31.00, z=491.13], xc['Zombie'/60909, l='MpServer', x=697.47, y=57.00, z=470.47], xc['Zombie'/60903, l='MpServer', x=675.03, y=27.00, z=520.50], uq['Bat'/50229, l='MpServer', x=652.84, y=48.10, z=461.13], wy['Slime'/58975, l='MpServer', x=666.69, y=30.00, z=448.31]]
Retry entities: 0 total; []
Server brand: vanilla
Server type: Integrated singleplayer server
Stacktrace:
at biz.a(SourceFile:284)
at azd.b(SourceFile:1951)
at azd.e(SourceFile:713)
at net.minecraft.client.main.Main.main(SourceFile:103)

– System Details –
Details:
Minecraft Version: 1.7.2
Operating System: Windows 8 (x86) version 6.2
Java Version: 1.7.0_45, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
Memory: 70833424 bytes (67 MB) / 256643072 bytes (244 MB) up to 518979584 bytes (494 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
AABB Pool Size: 2563 (143528 bytes; 0 MB) allocated, 2 (112 bytes; 0 MB) used
IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
Launched Version: 1.7.2
LWJGL: 2.9.0
OpenGL: Intel(R) HD Graphics 4000 GL version 4.0.0 - Build 10.18.10.3262, Intel
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs: []
Current Language: English (US)
Profiler Position: N/A (disabled)
Vec3 Pool Size: 3406 (190736 bytes; 0 MB) allocated, 18 (1008 bytes; 0 MB) used
Anisotropic Filtering: Off (1)