[18:31:50] [Server thread/ERROR]: Could not pass event PlayerJoinEvent to ServerSelectorX vPremium-2.0.0-beta
org.bukkit.event.EventException: null
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:320) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:529) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:514) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.PlayerList.a(PlayerList.java:176) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.LoginListener.c(LoginListener.java:154) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.LoginListener.tick(LoginListener.java:53) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.NetworkManager.a(NetworkManager.java:220) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.ServerConnection.c(ServerConnection.java:129) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.MinecraftServer.b(MinecraftServer.java:1099) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.DedicatedServer.b(DedicatedServer.java:393) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.MinecraftServer.a(MinecraftServer.java:978) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at net.minecraft.server.v1_15_R1.MinecraftServer.run(MinecraftServer.java:823) [spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_231]
Caused by: xyz.derkades.serverselectorx.lib.nbtapi.NbtApiException: Error while calling the method 'null', loaded: false.
        at xyz.derkades.serverselectorx.lib.nbtapi.utils.nmsmappings.ReflectionMethod.run(ReflectionMethod.java:149) ~[?:?]
        at xyz.derkades.serverselectorx.lib.nbtapi.NBTItem.getCompound(NBTItem.java:33) ~[?:?]
        at xyz.derkades.serverselectorx.lib.nbtapi.NBTReflectionUtil.setData(NBTReflectionUtil.java:468) ~[?:?]
        at xyz.derkades.serverselectorx.lib.nbtapi.NBTCompound.setInteger(NBTCompound.java:92) ~[?:?]
        at xyz.derkades.serverselectorx.lib.derkutils.bukkit.ItemBuilder.hideFlags(ItemBuilder.java:169) ~[?:?]
        at xyz.derkades.serverselectorx.Main.getItemBuilderFromItemSection(Main.java:249) ~[?:?]
        at xyz.derkades.serverselectorx.GiveItemsListener.giveItems(GiveItemsListener.java:87) ~[?:?]
        at xyz.derkades.serverselectorx.GiveItemsListener.onJoin(GiveItemsListener.java:37) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_231]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_231]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_231]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_231]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:316) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        ... 13 more
Caused by: java.lang.NullPointerException
        at xyz.derkades.serverselectorx.lib.nbtapi.utils.nmsmappings.ReflectionMethod.run(ReflectionMethod.java:147) ~[?:?]
        at xyz.derkades.serverselectorx.lib.nbtapi.NBTItem.getCompound(NBTItem.java:33) ~[?:?]
        at xyz.derkades.serverselectorx.lib.nbtapi.NBTReflectionUtil.setData(NBTReflectionUtil.java:468) ~[?:?]
        at xyz.derkades.serverselectorx.lib.nbtapi.NBTCompound.setInteger(NBTCompound.java:92) ~[?:?]
        at xyz.derkades.serverselectorx.lib.derkutils.bukkit.ItemBuilder.hideFlags(ItemBuilder.java:169) ~[?:?]
        at xyz.derkades.serverselectorx.Main.getItemBuilderFromItemSection(Main.java:249) ~[?:?]
        at xyz.derkades.serverselectorx.GiveItemsListener.giveItems(GiveItemsListener.java:87) ~[?:?]
        at xyz.derkades.serverselectorx.GiveItemsListener.onJoin(GiveItemsListener.java:37) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_231]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_231]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_231]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_231]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:316) ~[spigot-1.15.1.jar:git-Spigot-2ee05fe-d31f05f]
        ... 13 more