[1.10.2] Ticking Entity NPE

I started to add in entities into my mod and everything seemed to be working correctly but when I tried to kill one, I got a Ticking Entity NPE.

public class EntityWight extends EntityMob
{
    public EntityWight(World worldIn)
    {
        super(worldIn);

        setSize(0.55F, 1.5F);
        stepHeight = 0.5F;
        isImmuneToFire = true;
    }

    @Override
    protected void initEntityAI()
    {
        tasks.addTask(0, new EntityAISwimming(this));
        tasks.addTask(1, new EntityAIWander(this, 0.25D));
        targetTasks.addTask(0, new EntityAINearestAttackableTarget(this, EntityPlayer.class, true));
    }

    @Override
    protected void applyEntityAttributes()
    {
        super.applyEntityAttributes();

        getEntityAttribute(SharedMonsterAttributes.MAX_HEALTH).setBaseValue(10.0D);
        getEntityAttribute(SharedMonsterAttributes.FOLLOW_RANGE).setBaseValue(32.0D);
        getEntityAttribute(SharedMonsterAttributes.MOVEMENT_SPEED).setBaseValue(0.3D);
        getEntityAttribute(SharedMonsterAttributes.ATTACK_DAMAGE).setBaseValue(3.5D);
    }

    @Override
    public boolean getCanSpawnHere()
    {
        return this.worldObj.getDifficulty() != EnumDifficulty.PEACEFUL && super.getCanSpawnHere();
    }

    @Override
    protected Item getDropItem()
    {
        return Items.BONE;
    }
}

---- Minecraft Crash Report ----
// On the bright side, I bought you a teddy bear!

Time: 8/4/16 12:42 PM
Description: Ticking entity

java.lang.NullPointerException: Ticking entity
at net.minecraft.entity.ai.EntityLookHelper.setLookPositionWithEntity(EntityLookHelper.java:31)
at net.minecraft.entity.ai.EntityAIAttackMelee.updateTask(EntityAIAttackMelee.java:114)
at net.minecraft.entity.ai.EntityAITasks.onUpdateTasks(EntityAITasks.java:112)
at net.minecraft.entity.EntityLiving.updateEntityActionState(EntityLiving.java:846)
at net.minecraft.entity.EntityLivingBase.onLivingUpdate(EntityLivingBase.java:2392)
at net.minecraft.entity.EntityLiving.onLivingUpdate(EntityLiving.java:643)
at net.minecraft.entity.monster.EntityMob.onLivingUpdate(EntityMob.java:56)
at net.minecraft.entity.EntityLivingBase.onUpdate(EntityLivingBase.java:2218)
at net.minecraft.entity.EntityLiving.onUpdate(EntityLiving.java:342)
at net.minecraft.entity.monster.EntityMob.onUpdate(EntityMob.java:64)
at net.minecraft.world.World.updateEntityWithOptionalForce(World.java:2106)
at net.minecraft.world.WorldServer.updateEntityWithOptionalForce(WorldServer.java:872)
at net.minecraft.world.World.updateEntity(World.java:2073)
at net.minecraft.world.World.updateEntities(World.java:1886)
at net.minecraft.world.WorldServer.updateEntities(WorldServer.java:644)
at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:783)
at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:687)
at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:156)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:536)
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 --
Thread: Server thread
Stacktrace:
at net.minecraft.entity.ai.EntityLookHelper.setLookPositionWithEntity(EntityLookHelper.java:31)
at net.minecraft.entity.ai.EntityAIAttackMelee.updateTask(EntityAIAttackMelee.java:114)
at net.minecraft.entity.ai.EntityAITasks.onUpdateTasks(EntityAITasks.java:112)
at net.minecraft.entity.EntityLiving.updateEntityActionState(EntityLiving.java:846)
at net.minecraft.entity.EntityLivingBase.onLivingUpdate(EntityLivingBase.java:2392)
at net.minecraft.entity.EntityLiving.onLivingUpdate(EntityLiving.java:643)
at net.minecraft.entity.monster.EntityMob.onLivingUpdate(EntityMob.java:56)
at net.minecraft.entity.EntityLivingBase.onUpdate(EntityLivingBase.java:2218)
at net.minecraft.entity.EntityLiving.onUpdate(EntityLiving.java:342)
at net.minecraft.entity.monster.EntityMob.onUpdate(EntityMob.java:64)
at net.minecraft.world.World.updateEntityWithOptionalForce(World.java:2106)
at net.minecraft.world.WorldServer.updateEntityWithOptionalForce(WorldServer.java:872)
at net.minecraft.world.World.updateEntity(World.java:2073)

-- Entity being ticked --
Details:
Entity Type: nex.wight (nex.entity.hostile.EntityWight)
Entity ID: 887
Entity Name: Wight
Entity's Exact location: -331.94, 65.88, 152.38
Entity's Block location: World: (-332,65,152), Chunk: (at 4,4,8 in -21,9; contains blocks -336,0,144 to -321,255,159), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
Entity's Momentum: 0.00, -0.08, 0.00
Entity's Passengers: []
Entity's Vehicle: ~~ERROR~~ NullPointerException: null
Stacktrace:
at net.minecraft.world.World.updateEntities(World.java:1886)
at net.minecraft.world.WorldServer.updateEntities(WorldServer.java:644)

-- Affected level --
Details:
Level name: New World
All players: 1 total; [EntityPlayerMP['Player715'/219, l='New World', x=-329.30, y=65.88, z=152.34]]
Chunk stats: ServerChunkCache: 662 Drop: 0
Level seed: 6570541280075044611
Level generator: ID 00 - default, ver 1. Features enabled: false
Level generator options: 
Level spawn location: World: (0,0,0), Chunk: (at 0,0,0 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: 0 game time, 0 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: ~~ERROR~~ NullPointerException: null
Stacktrace:
at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:783)
at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:687)
at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:156)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:536)
at java.lang.Thread.run(Thread.java:745)

-- System Details --
Details:
Minecraft Version: 1.10.2
Operating System: Windows 10 (amd64) version 10.0
Java Version: 1.8.0_101, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 664759608 bytes (633 MB) / 1288699904 bytes (1229 MB) up to 1901592576 bytes (1813 MB)
JVM Flags: 0 total; 
IntCache: cache: 1, tcache: 10, allocated: 0, tallocated: 0
FML: MCP 9.32 Powered by Forge 12.18.1.2011 8 mods loaded, 8 mods active
States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored
UCHIJAAAA	mcp{9.19} [Minecraft Coder Pack] (minecraft.jar) 
UCHIJAAAA	FML{8.0.99.99} [Forge Mod Loader] (forgeSrc-1.10.2-12.18.1.2011.jar) 
UCHIJAAAA	Forge{12.18.1.2011} [Minecraft Forge] (forgeSrc-1.10.2-12.18.1.2011.jar) 
UCHIJAAAA	nex{@VERSION@} [NetherEx] (NetherEx_main) 
UCHIJAAAA	JEI{3.7.8.234} [Just Enough Items] (jei_1.10.2-3.7.8.234.jar) 
UCHIJAAAA	mantle{1.10.2-0.10.4.jenkins163} [Mantle] (Mantle-1.10.2-0.10.4.jar) 
UCHIJAAAA	tconstruct{1.10-2.3.3a.jenkins271} [Tinkers' Construct] (TConstruct-1.10-2.3.3a.jar) 
UCHIJAAAA	worldedit{6.1.3} [WorldEdit] (worldedit-forge-mc1.9.4-6.1.3-dist.jar) 
Loaded coremods (and transformers): 
GL info: ~~ERROR~~ RuntimeException: No OpenGL context found in the current thread.
Pulsar/tconstruct loaded Pulses: 
	- TinkerCommons (Enabled/Forced)
	- TinkerWorld (Enabled/Not Forced)
	- TinkerTools (Enabled/Not Forced)
	- TinkerSmeltery (Enabled/Not Forced)
	- TinkerGadgets (Enabled/Not Forced)
	- TinkerOredict (Enabled/Forced)
	- TinkerIntegration (Enabled/Forced)
	- TinkerFluids (Enabled/Forced)
	- TinkerMaterials (Enabled/Forced)

Profiler Position: N/A (disabled)
Player Count: 1 / 8; [EntityPlayerMP['Player715'/219, l='New World', x=-329.30, y=65.88, z=152.34]]
Type: Integrated Server (map_client.txt)
Is Modded: Definitely; Client brand changed to 'fml,forge'