[Server thread/WARN]: Couldn't look up profile properties for com.mojang.authlib.GameProfile@4eaf6f84[id=8fec-36ea-b9e7-e25166751739,name=hu,properties={},legacy=false]
com.mojang.authlib.exceptions.AuthenticationException: The client has sent too many requests within a certain amount of time
        at com.mojang.authlib.yggdrasil.YggdrasilAuthenticationService.makeRequest(YggdrasilAuthenticationService.java:65) ~[server-1.7.10.jar:?]
        at com.mojang.authlib.yggdrasil.YggdrasilMinecraftSessionService.fillProfileProperties(YggdrasilMinecraftSessionService.java:135) [server-1.7.10.jar:?]
        at noppes.npcs.DataDisplay.loadProfile(DataDisplay.java:141) [DataDisplay.class:?]
        at noppes.npcs.DataDisplay.readToNBT(DataDisplay.java:108) [DataDisplay.class:?]
        at noppes.npcs.entity.EntityNPCInterface.func_70037_a(EntityNPCInterface.java:926) [EntityNPCInterface.class:?]
        at noppes.npcs.entity.EntityCustomNpc.func_70037_a(EntityCustomNpc.java:23) [EntityCustomNpc.class:?]
        at net.minecraft.entity.Entity.func_70020_e(Entity.java:1664) [sa.class:?]
        at net.minecraft.entity.EntityList.func_75615_a(EntityList.java:173) [sg.class:?]
        at net.minecraft.world.chunk.storage.AnvilChunkLoader.loadEntities(AnvilChunkLoader.java:487) [aqk.class:?]
        at net.minecraftforge.common.chunkio.ChunkIOProvider.callStage2(ChunkIOProvider.java:44) [ChunkIOProvider.class:1.7.10-R0.1-SNAPSHOT]
        at net.minecraftforge.common.chunkio.ChunkIOProvider.callStage2(ChunkIOProvider.java:15) [ChunkIOProvider.class:1.7.10-R0.1-SNAPSHOT]
        at net.minecraftforge.common.util.AsynchronousExecutor.skipQueue(AsynchronousExecutor.java:344) [AsynchronousExecutor.class:1.7.10-R0.1-SNAPSHOT]
        at net.minecraftforge.common.util.AsynchronousExecutor.getSkipQueue(AsynchronousExecutor.java:302) [AsynchronousExecutor.class:1.7.10-R0.1-SNAPSHOT]
        at net.minecraftforge.common.chunkio.ChunkIOExecutor.syncChunkLoad(ChunkIOExecutor.java:12) [ChunkIOExecutor.class:1.7.10-R0.1-SNAPSHOT]
        at net.minecraft.world.gen.ChunkProviderServer.loadChunk(ChunkProviderServer.java:197) [ms.class:?]
        at net.minecraft.world.gen.ChunkProviderServer.func_73158_c(ChunkProviderServer.java:170) [ms.class:?]
        at net.minecraft.world.gen.ChunkProviderServer.func_73154_d(ChunkProviderServer.java:315) [ms.class:?]
        at net.minecraft.world.World.func_72964_e(World.java:751) [ahb.class:?]
        at net.minecraft.world.World.func_147439_a(World.java:677) [ahb.class:?]
        at net.minecraft.block.BlockFire.getChanceToEncourageFire(BlockFire.java:555) [alb.class:?]
        at net.minecraft.block.BlockFire.func_149845_m(BlockFire.java:303) [alb.class:?]
        at net.minecraft.block.BlockFire.func_149674_a(BlockFire.java:174) [alb.class:?]
        at net.minecraft.world.WorldServer.func_72955_a(WorldServer.java:702) [mt.class:?]
        at net.minecraft.world.WorldServer.func_72835_b(WorldServer.java:284) [mt.class:?]
        at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:931) [MinecraftServer.class:?]
        at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:431) [lt.class:?]
        at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:809) [MinecraftServer.class:?]
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:669) [MinecraftServer.class:?]
        at java.lang.Thread.run(Thread.java:745) [?:1.8.0_111]

Spigot核心主要开发者md_5在spigotmc.org回答了这个问题：
https://www.spigotmc.org/threads ... ount-of-time.24838/

但我看到这是一个NPC实体，名字为"hu"。
请提供这个报错是在什么情况下触发的，以及"hu"是什么。

实体为一位不在线的玩家；报错是在进入某些区块里触发的，或者是一些存在NPC（由npcmod生成的）的区块，加载区块后触发报错，一直刷屏，直至玩家与服务器断开连接。