Error

gistfile1.txt

2013-02-17 13:12:43 [SEVERE] [TickThreading] Exception during entity tick at rX: -204, rZ: 23, hashCode: 1507124:
java.lang.IndexOutOfBoundsException: Index: 1, Size: 1
        at java.util.ArrayList.rangeCheck(ArrayList.java:604)
        at java.util.ArrayList.get(ArrayList.java:382)
        at zz.getEntitiesWithinAABBForEntity(Chunk.java:49)
        at yc.getEntitiesWithinAABBExcludingEntity(World.java:378)
        at yc.getCollidingBoundingBoxes(World.java:332)
        at lq.d(Entity.java:108)
        at md.e(EntityLiving.java:123)
        at md.c(EntityLiving.java:241)
        at md.j_(EntityLiving.java:843)
        at ow.j_(SourceFile:106)
        at yc.a(World.java:150)
        at in.a(WorldServer.java:647)
        at yc.g(World.java:2255)
        at me.nallar.tickthreading.minecraft.tickregion.EntityTickRegion.doTick(EntityTickRegion.java:48)
        at me.nallar.tickthreading.minecraft.tickregion.TickRegion.run(TickRegion.java:42)
        at me.nallar.tickthreading.minecraft.ThreadManager$2.run(ThreadManager.java:89)
        at me.nallar.tickthreading.minecraft.ThreadManager$1.run(ThreadManager.java:40)
        at me.nallar.tickthreading.minecraft.ThreadManager$ServerWorkThread.run(ThreadManager.java:150)