2013-02-07 15:16:59 [SEVERE] net.minecraft.server.v1_4_R1.ReportedException: Exception ticking world entities
2013-02-07 15:16:59 [SEVERE]    at net.minecraft.server.v1_4_R1.MinecraftServer.r(MinecraftServer.java:575)
2013-02-07 15:16:59 [SEVERE]    at net.minecraft.server.v1_4_R1.DedicatedServer.r(DedicatedServer.java:224)
2013-02-07 15:16:59 [SEVERE]    at net.minecraft.server.v1_4_R1.MinecraftServer.q(MinecraftServer.java:485)
2013-02-07 15:16:59 [SEVERE]    at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java:420)
2013-02-07 15:16:59 [SEVERE]    at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:849)
2013-02-07 15:16:59 [SEVERE] Caused by: java.lang.NullPointerException
2013-02-07 15:16:59 [SEVERE]    at net.minecraft.server.v1_4_R1.World.tickEntities(World.java:1250)
2013-02-07 15:16:59 [SEVERE]    at net.minecraft.server.v1_4_R1.WorldServer.tickEntities(WorldServer.java:479)
2013-02-07 15:16:59 [SEVERE]    at net.minecraft.server.v1_4_R1.MinecraftServer.r(MinecraftServer.java:571)
2013-02-07 15:16:59 [SEVERE]    ... 4 more
2013-02-07 15:16:59 [SEVERE] Encountered an unexpected exception ReportedException
net.minecraft.server.v1_4_R1.ReportedException: Exception ticking world entities
>       at net.minecraft.server.v1_4_R1.MinecraftServer.r(MinecraftServer.java:575)
>       at net.minecraft.server.v1_4_R1.DedicatedServer.r(DedicatedServer.java:224)
>       at net.minecraft.server.v1_4_R1.MinecraftServer.q(MinecraftServer.java:485)
>       at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java:420)
>       at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:849)
Caused by: java.lang.NullPointerException
>       at net.minecraft.server.v1_4_R1.World.tickEntities(World.java:1250)
>       at net.minecraft.server.v1_4_R1.WorldServer.tickEntities(WorldServer.java:479)
>       at net.minecraft.server.v1_4_R1.MinecraftServer.r(MinecraftServer.java:571)
>       ... 4 more
2013-02-07 15:16:59 [SEVERE] This crash report has been saved to: /home/mccraft/skyblock/./crash-reports/crash-2013-02-07_15.16.59-server.txt