The entity 'Necromancer' at the location -117.89, 70, -239.23 is causing issues while ticking (help)

---- Minecraft Crash Report ----

// I just don't know what went wrong :(

's Exact location: -117.89, 70.00, -239.23

    Entity's Block location: World: (-118,70,-240), Chunk: (at 10,4,0 in -8,-15; contains blocks -128,0,-240 to -113,255,-225), Region: (-1,-1; contains chunks -32,-32 to -1,-1, blocks -512,0,-512 to -1,255,-1)

    Entity's Momentum: 0.00, -0.08, 0.00

    Entity's Passengers: []

    Entity's Vehicle: ~~ERROR~~ NullPointerException: null

Stacktrace:

    at net.minecraft.world.World.func_217390_a(World.java:554) ~[?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:mixin:APP:securitycraft.mixins.json:piston.WorldMixin,pl:mixin:APP:enhancedcelestials.mixins.json:MixinWorld,pl:mixin:A,pl:runtimedistcleaner:A}

    at net.minecraft.world.server.ServerWorld.func_72835_b(ServerWorld.java:405) ~[?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:mixin:APP:mca.mixin.json:MixinServerWorld,pl:mixin:APP:enhancedcelestials.mixins.json:MixinServerWorld,pl:mixin:A,pl:runtimedistcleaner:A}

-- Affected level --

Details:

    All players: 1 total; [ServerPlayerEntity['vesomarxd123'/281, l='ServerLevel[world]', x=-120.00, y=70.00, z=-238.55]]

    Chunk stats: ServerChunkCache: 2186

    Level dimension: minecraft:overworld

    Level spawn location: World: (-80,67,-160), Chunk: (at 0,4,0 in -5,-10; contains blocks -80,0,-160 to -65,255,-145), Region: (-1,-1; contains chunks -32,-32 to -1,-1, blocks -512,0,-512 to -1,255,-1)

    Level time: 2804315 game time, 109345 day time

    Level name: world

    Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false

    Level weather: Rain time: 126789 (now: false), thunder time: 71213 (now: false)

    Known server brands: forge

    Level was modded: true

    Level storage version: 0x04ABD - Anvil

Stacktrace:

    at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:851) ~[?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:mixin:APP:betterendforge.mixins.json:MinecraftServerMixin,pl:mixin:A,pl:runtimedistcleaner:A}

    at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:291) ~[?:?] {re:classloading,pl:accesstransformer:B}

    at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:787) ~[?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:mixin:APP:betterendforge.mixins.json:MinecraftServerMixin,pl:mixin:A,pl:runtimedistcleaner:A}

    at net.minecraft.server.MinecraftServer.func_240802_v_(MinecraftServer.java:642) ~[?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:mixin:APP:betterendforge.mixins.json:MinecraftServerMixin,pl:mixin:A,pl:runtimedistcleaner:A}

    at net.minecraft.server.MinecraftServer.func_240783_a_(MinecraftServer.java:232) ~[?:?] {re:mixin,pl:accesstransformer:B,pl:runtimedistcleaner:A,re:classloading,pl:accesstransformer:B,pl:mixin:APP:betterendforge.mixins.json:MinecraftServerMixin,pl:mixin:A,pl:runtimedistcleaner:A}

    at java.lang.Thread.run(Thread.java:750) [?:1.8.0_342] {}