Помогите Краш сервер Скелетом

Здравствуйте
Проблема которую исправить немогу.
В среднем 3 раза на день, сервер крашится вот с таким логом:

Спойлер: Краш лог

Код:

-- Head --
Stacktrace:
    at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901)
    at java.util.ArrayList$Itr.next(ArrayList.java:851)
    at net.minecraft.entity.ai.EntityAITasks.func_75774_a(SourceFile:101)
    at net.minecraft.entity.EntityLiving.func_70619_bc(EntityLiving.java:582)
    at net.minecraft.entity.EntityLivingBase.func_70636_d(EntityLivingBase.java:2066)
    at net.minecraft.entity.EntityLiving.func_70636_d(EntityLiving.java:388)
    at net.minecraft.entity.monster.EntityMob.func_70636_d(EntityMob.java:36)
    at net.minecraft.entity.monster.EntitySkeleton.func_70636_d(EntitySkeleton.java:172)
    at net.minecraft.entity.EntityLivingBase.func_70071_h_(EntityLivingBase.java:1899)
    at net.minecraft.entity.EntityLiving.func_70071_h_(EntityLiving.java:213)
    at net.minecraft.entity.monster.EntityMob.func_70071_h_(EntityMob.java:41)
    at net.minecraft.world.World.func_72866_a(World.java:2655)
    at net.minecraft.world.WorldServer.func_72866_a(WorldServer.java:837)
    at net.minecraft.world.World.func_72870_g(World.java:2607)

-- Entity being ticked --
Details:
    Entity Type: Skeleton (net.minecraft.entity.monster.EntitySkeleton)
    Entity ID: 955351
    Entity Name: Skeleton
    Entity's Exact location: 172.02, 77.77, -431.77
    Entity's Block location: World: (172,77,-432), Chunk: (at 12,4,0 in 10,-27; contains blocks 160,0,-432 to 175,255,-417), Region: (0,-1; contains chunks 0,-32 to 31,-1, blocks 0,0,-512 to 511,255,-1)
    Entity's Momentum: 0.16, 0.28, 0.29
Stacktrace:
    at net.minecraft.world.World.func_72939_s(World.java:2423)
    at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:669)

-- Affected level --
Details:
    Level name: DIM-1
    All players: 1 total; [EntityPlayerMP['Proff'/915954, l='DIM-1', x=171.30, y=77.50, z=-432.70](Proff at 171.30000001192093,77.5,-432.69999998807907)]
    Chunk stats: ServerChunkCache: 477 Drop: 0
    Level seed: -8711569751282499038
    Level generator: ID 04 - RWG, ver 0. Features enabled: true
    Level generator options:
    Level spawn location: World: (0,64,0), Chunk: (at 0,4,0 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)
    Level time: 9100281 game time, 9100281 day time
    Level dimension: -1
    Level storage version: 0x04ABD - Anvil
    Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
    Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false
Stacktrace:
    at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:954)
    at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:431)
    at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:809)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:669)
    at java.lang.Thread.run(Thread.java:745)

Не могу понять из за чего вообще такое происходит.
Прошу помощи по данной проблеме
Спасибо за внимание.