Could not pass event PlayerInteractEvent to CustomBosses v2.10.29
org.bukkit.event.EventException: null
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[minecraft_server.jar:git-Spigot-da42974-8f47214]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[minecraft_server.jar:git-Spigot-da42974-8f47214]
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:499) [minecraft_server.jar:git-Spigot-da42974-8f47214]
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:484) [minecraft_server.jar:git-Spigot-da42974-8f47214]
at org.bukkit.craftbukkit.v1_12_R1.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:234) [minecraft_server.jar:git-Spigot-da42974-8f47214]
at net.minecraft.server.v1_12_R1.PlayerInteractManager.a(PlayerInteractManager.java:458) [minecraft_server.jar:git-Spigot-da42974-8f47214]
at net.minecraft.server.v1_12_R1.PlayerConnection.a(PlayerConnection.java:945) [minecraft_server.jar:git-Spigot-da42974-8f47214]
at net.minecraft.server.v1_12_R1.PacketPlayInUseItem.a(PacketPlayInUseItem.java:37) [minecraft_server.jar:git-Spigot-da42974-8f47214]
at net.minecraft.server.v1_12_R1.PacketPlayInUseItem.a(PacketPlayInUseItem.java:1) [minecraft_server.jar:git-Spigot-da42974-8f47214]
at net.minecraft.server.v1_12_R1.PlayerConnectionUtils$1.run(SourceFile:13) [minecraft_server.jar:git-Spigot-da42974-8f47214]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_45]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_45]
at net.minecraft.server.v1_12_R1.SystemUtils.a(SourceFile:46) [minecraft_server.jar:git-Spigot-da42974-8f47214]
at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:748) [minecraft_server.jar:git-Spigot-da42974-8f47214]
at net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:406) [minecraft_server.jar:git-Spigot-da42974-8f47214]
at net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:679) [minecraft_server.jar:git-Spigot-da42974-8f47214]
at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:577) [minecraft_server.jar:git-Spigot-da42974-8f47214]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_45]
Caused by: java.lang.UnsupportedOperationException: Not supported.
at org.bukkit.craftbukkit.v1_12_R1.entity.CraftSkeleton.setSkeletonType(CraftSkeleton.java:36) ~[minecraft_server.jar:git-Spigot-da42974-8f47214]
at net.aminecraftdev.custombosses.zcore.c.EntityUtils.getWitherSkeleton(EntityUtils.java:20) ~[?:?]
at net.aminecraftdev.custombosses.zcore.c.CompositeRoot$BossUtils.spawnLivingEntity(CompositeRoot.java:411) ~[?:?]
at net.aminecraftdev.custombosses.zcore.c.CompositeRoot$BossUtils.spawnBoss(CompositeRoot.java:527) ~[?:?]
at net.aminecraftdev.custombosses.listeners.boss.pre.BossSpawnListener.onBossSpawn(BossSpawnListener.java:88) ~[?:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_45]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_45]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_45]
at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_45]
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302) ~[minecraft_server.jar:git-Spigot-da42974-8f47214]
... 17 more