Server criushing from time to time, can you say pls, what is problem? In Logs I can't find error description, I see it only in consol.

I using only two plugins, it's SinglePlayerSleep and SkinsRestorer.

> [21:04:45] [Spigot Watchdog Thread/ERROR]: Server thread dump (Look for plugins here before reporting to Spigot!):
> [21:04:45] [Spigot Watchdog Thread/ERROR]: ------------------------------
> [21:04:45] [Spigot Watchdog Thread/ERROR]: Current Thread: Server thread
> [21:04:45] [Spigot Watchdog Thread/ERROR]: PID: 20 | Suspended: false | Native: false | State: RUNNABLE
> [21:04:45] [Spigot Watchdog Thread/ERROR]: Stack:
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.world.entity.ai.BehaviorController$1.encode(SourceFile:103)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.world.entity.ai.BehaviorController$1.encode(SourceFile:75)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//com.mojang.serialization.MapCodec$MapCodecCodec.encode(MapCodec.java:96)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//com.mojang.serialization.Encoder.encodeStart(Encoder.java:14)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//com.mojang.serialization.codecs.FieldEncoder.encode(FieldEncoder.java:24)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//com.mojang.serialization.MapCodec$1.encode(MapCodec.java:39)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//com.mojang.serialization.MapCodec$MapCodecCodec.encode(MapCodec.java:96)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//com.mojang.serialization.Encoder.encodeStart(Encoder.java:14)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.world.entity.ai.BehaviorController.a(SourceFile:160)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.world.entity.EntityLiving.saveData(EntityLiving.java:758)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.world.entity.player.EntityHuman.saveData(EntityHuman.java:833)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.server.level.EntityPlayer.saveData(EntityPlayer.java:438)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.world.entity.Entity.save(Entity.java:1794)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.world.level.storage.WorldNBTStorage.save(WorldNBTStorage.java:37)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.server.players.PlayerList.savePlayerFile(PlayerList.java:467)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.server.players.PlayerList.disconnect(PlayerList.java:500)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.server.network.PlayerConnection.a(PlayerConnection.java:1679)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.network.NetworkManager.handleDisconnection(NetworkManager.java:404)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.server.network.ServerConnection.c(ServerConnection.java:192)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.server.MinecraftServer.b(MinecraftServer.java:1319)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.server.dedicated.DedicatedServer.b(DedicatedServer.java:436)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.server.MinecraftServer.a(MinecraftServer.java:1200)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.server.MinecraftServer.x(MinecraftServer.java:1027)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.server.MinecraftServer.lambda$0(MinecraftServer.java:307)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: app//net.minecraft.server.MinecraftServer$$Lambda$3765/0x000000080134db10.run(Unknown Source)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: [email protected]/java.lang.Thread.run(Thread.java:831)
> [21:04:45] [Spigot Watchdog Thread/ERROR]: ------------------------------
> [21:04:45] [Spigot Watchdog Thread/ERROR]: Entire Thread Dump: