Description: Ticking entity

java.lang.ClassCastException: net.minecraft.entity.monster.EntitySkeleton cannot be cast to net.minecraft.entity.player.EntityPlayer
at xreliquary.items.ItemMobCharm.onLivingUpdate(ItemMobCharm.java:210)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_1471_ItemMobCharm_onLivingUpdate_LivingUpdateEvent.invoke(.dynamic)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:182)
at net.minecraftforge.common.ForgeHooks.onLivingUpdate(ForgeHooks.java:580)
at net.minecraft.entity.EntityLivingBase.func_70071_h_(EntityLivingBase.java:2095)
at net.minecraft.entity.EntityLiving.func_70071_h_(EntityLiving.java:295)
at net.minecraft.entity.monster.EntityMob.func_70071_h_(EntityMob.java:50)
at net.minecraft.world.World.func_72866_a(World.java:1993)
at net.minecraft.world.WorldServer.func_72866_a(WorldServer.java:832)
at net.minecraft.world.World.func_72870_g(World.java:1955)
at net.minecraft.world.World.func_72939_s(World.java:1759)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:613)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:767)
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:397)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:668)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526)
at java.lang.Thread.run(Unknown Source)

A detailed walkthrough of the error, its code path and all known details is as follows:

-- Head --
Thread: Server thread
Stacktrace:
at xreliquary.items.ItemMobCharm.onLivingUpdate(ItemMobCharm.java:210)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_1471_ItemMobCharm_onLivingUpdate_LivingUpdateEvent.invoke(.dynamic)
at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:182)
at net.minecraftforge.common.ForgeHooks.onLivingUpdate(ForgeHooks.java:580)
at net.minecraft.entity.EntityLivingBase.func_70071_h_(EntityLivingBase.java:2095)
at net.minecraft.entity.EntityLiving.func_70071_h_(EntityLiving.java:295)
at net.minecraft.entity.monster.EntityMob.func_70071_h_(EntityMob.java:50)
at net.minecraft.world.World.func_72866_a(World.java:1993)
at net.minecraft.world.WorldServer.func_72866_a(WorldServer.java:832)
at net.minecraft.world.World.func_72870_g(World.java:1955)

-- Entity being ticked --
Details:
Entity Type: minecraft:skeleton (net.minecraft.entity.monster.EntitySkeleton)
Entity ID: 258
Entity Name: Skeleton
Entity's Exact location: 669,30, 22,00, -1866,33
Entity's Block location: World: (669,22,-1867), Chunk: (at 13,1,5 in 41,-117; contains blocks 656,0,-1872 to 671,255,-1857), Region: (1,-4; contains chunks 32,-128 to 63,-97, blocks 512,0,-2048 to 1023,255,-1537)
Entity's Momentum: -0,21, 0,40, -0,53
Entity's Passengers: []
Entity's Vehicle: ERROR NullPointerException: null
Stacktrace:
at net.minecraft.world.World.func_72939_s(World.java:1759)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:613)

-- Affected level --
Details:
Level name: world
All players: 1 total; [EntityPlayerMP['kakaoninja'/478, l='world', x=669,70, y=21,00, z=-1864,30]]
Chunk stats: ServerChunkCache: 1189 Drop: 0
Level seed: 6194662872699361910
Level generator: ID 07 - OTG, ver 0. Features enabled: true
Level generator options: OpenTerrainGenerator
Level spawn location: World: (676,64,-1738), Chunk: (at 4,4,6 in 42,-109; contains blocks 672,0,-1744 to 687,255,-1729), Region: (1,-4; contains chunks 32,-128 to 63,-97, blocks 512,0,-2048 to 1023,255,-1537)
Level time: 262942 game time, 344008 day time
Level dimension: 0
Level storage version: 0x04ABD - Anvil
Level weather: Rain time: 10414 (now: true), thunder time: 93828 (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:767)
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:397)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:668)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:526)
at java.lang.Thread.run(Unknown Source)

Just fixed this in the latest release on curseforge