Walking throught water

---- Minecraft Crash Report ----
// There are four lights!

Time: 18/01/15 21:52
Description: Exception ticking world

java.lang.NullPointerException: Exception ticking world
at azi.a(SourceFile:124)
at azi.apply(SourceFile:121)
at beh.a(SourceFile:53)
at beh.apply(SourceFile:50)
at bei.a(SourceFile:67)
at bei.a(SourceFile:90)
at azh.f(SourceFile:49)
at azh.c(SourceFile:39)
at bff.a(SourceFile:551)
at aqr.a(SourceFile:290)
at bif.b(SourceFile:20)
at arv.a(SourceFile:261)
at arv.a(SourceFile:49)
at arj.a(SourceFile:389)
at asa.a(SourceFile:143)
at bgt.a(SourceFile:472)
at qt.a(SourceFile:174)
at bff.a(SourceFile:863)
at qt.c(SourceFile:104)
at qt.d(SourceFile:116)
at aqr.a(SourceFile:276)
at aqr.f(SourceFile:272)
at aqr.p(SourceFile:657)
at awk.b(SourceFile:66)
at ato.a(SourceFile:445)
at qu.h(SourceFile:383)
at qu.c(SourceFile:202)
at net.minecraft.server.MinecraftServer.A(SourceFile:600)
at net.minecraft.server.MinecraftServer.z(SourceFile:532)
at cyk.z(SourceFile:155)
at net.minecraft.server.MinecraftServer.run(SourceFile:448)
at java.lang.Thread.run(Thread.java:745)

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

– Head –
Stacktrace:
at azi.a(SourceFile:124)
at azi.apply(SourceFile:121)
at beh.a(SourceFile:53)
at beh.apply(SourceFile:50)
at bei.a(SourceFile:67)
at bei.a(SourceFile:90)
at azh.f(SourceFile:49)
at azh.c(SourceFile:39)
at bff.a(SourceFile:551)
at aqr.a(SourceFile:290)
at bif.b(SourceFile:20)
at arv.a(SourceFile:261)
at arv.a(SourceFile:49)
at arj.a(SourceFile:389)
at asa.a(SourceFile:143)
at bgt.a(SourceFile:472)
at qt.a(SourceFile:174)
at bff.a(SourceFile:863)
at qt.c(SourceFile:104)
at qt.d(SourceFile:116)
at aqr.a(SourceFile:276)
at aqr.f(SourceFile:272)
at aqr.p(SourceFile:657)
at awk.b(SourceFile:66)
at ato.a(SourceFile:445)
at qu.h(SourceFile:383)
at qu.c(SourceFile:202)

– Affected level –
Details:
Level name: New World
All players: 1 total; [qx['rwjnicol'/428349, l='New World', x=840.31, y=62.24, z=292.74]]
Chunk stats: ServerChunkCache: 788 Drop: 0
Level seed: -1794392526
Level generator: ID 00 - default, ver 1. Features enabled: true
Level generator options:
Level spawn location: 453.00,64.00,10.00 - World: (453,64,10), Chunk: (at 5,4,10 in 28,0; contains blocks 448,0,0 to 463,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 139483 game time, 193572 day time
Level dimension: 0
Level storage version: 0x04ABD - Anvil
Level weather: Rain time: 115815 (now: false), thunder time: 114036 (now: false)
Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Stacktrace:
at net.minecraft.server.MinecraftServer.A(SourceFile:600)
at net.minecraft.server.MinecraftServer.z(SourceFile:532)
at cyk.z(SourceFile:155)
at net.minecraft.server.MinecraftServer.run(SourceFile:448)
at java.lang.Thread.run(Thread.java:745)

– System Details –
Details:
Minecraft Version: 1.8.1
Operating System: Windows 8.1 (amd64) version 6.3
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 59659376 bytes (56 MB) / 525778944 bytes (501 MB) up to 1060372480 bytes (1011 MB)
JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
Profiler Position: N/A (disabled)
Player Count: 1 / 8; [qx['rwjnicol'/428349, l='New World', x=840.31, y=62.24, z=292.74]]
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.