Internal Error on my plugin

Hi, I am trying currently to develop a plugin that I call insurance which is suposed to allow you to enchant an item with it, and this item will be kept on your death, I have wrote the plugin and somewhy it keeps saying that An Internal error occured while trying to prefom this command.
Here is the plugin code:

Code:

package com.gmail.magnido9.Insurance;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;

import org.bukkit.ChatColor;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.enchantments.Enchantment;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.entity.PlayerDeathEvent;
import org.bukkit.event.player.PlayerRespawnEvent;
import org.bukkit.inventory.ItemStack;
import org.bukkit.plugin.java.JavaPlugin;


public class Insurance extends JavaPlugin implements Listener  {
    public CustomEnchant ench= new CustomEnchant(100);
    @Override
    public void onEnable() {
        LoadEnchantments();
        this.getServer().getPluginManager().registerEvents(this, this);
    }
   
    public java.util.List<ItemStack> DeathItems= new ArrayList<ItemStack>() ;
   
    @EventHandler
    public void onPlayerDeath(PlayerDeathEvent e) {
        e.getDrops();
        for (ItemStack item : e.getDrops()) {
            if(item.containsEnchantment(ench)) {
                DeathItems.add(item);
            }
        }       
    }
   
    @EventHandler
    public void onPlayerRespawn(PlayerRespawnEvent event) {
        for (ItemStack item : DeathItems) {
            event.getPlayer().getInventory().addItem(item);
        }
        DeathItems= new ArrayList<ItemStack>() ;
    }
   
    @Override
    public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
        if (cmd.getName().equalsIgnoreCase("insurance")) {
            if(!(sender instanceof Player)) {
                return false;
            }
            Player player = (Player)sender;
            ItemStack item= player.getInventory().getItemInMainHand();
            item.getItemMeta().getLore().add(ChatColor.GRAY + ench.getName());
            item.addUnsafeEnchantment(ench, 1);
            return true;
        }
        return false;
    }
   
    @SuppressWarnings("unchecked")
    public void onDisable() {
        try {
            Field byIdField=Enchantment.class.getDeclaredField("byId");
            Field byNameField=Enchantment.class.getDeclaredField("byName");
           
            byIdField.setAccessible(true);
            byNameField.setAccessible(true);
           
            HashMap<Integer, Enchantment> byId= (HashMap<Integer,Enchantment>) byIdField.get(null);
            HashMap<Integer, Enchantment> byName= (HashMap<Integer,Enchantment>) byNameField.get(null);
           
            if(byId.containsKey(ench.getId())) {
                byId.remove(ench.getId());
            }
            if(byName.containsKey(ench.getName())) {
                byName.remove(ench.getName());
            }

        }catch(Exception Ignored) {}
    }
    private void LoadEnchantments() {
        try {
            try {
                Field f = Enchantment.class.getDeclaredField("acceptingNew");
                f.setAccessible(true);
                f.set(null, true);
            }catch(Exception e) {
                e.printStackTrace();
            }
           
            try {
                Enchantment.registerEnchantment(ench);
            }catch(IllegalArgumentException e) {
                e.printStackTrace();
            }
        }catch(Exception e) {
            e.printStackTrace();
        }
    }

}

Here is the enchantment code:

Code:

package com.gmail.magnido9.Insurance;

import org.bukkit.enchantments.Enchantment;
import org.bukkit.enchantments.EnchantmentTarget;
import org.bukkit.event.Listener;
import org.bukkit.inventory.ItemStack;


public class CustomEnchant extends Enchantment implements Listener{

    public CustomEnchant(int id) {
        super(id);
        // TODO Auto-generated constructor stub
    }

    @Override
    public int getId() {
        return 100;
    }
   
    @Override
    public boolean canEnchantItem(ItemStack arg0) {
        return true;
    }

    @Override
    public boolean conflictsWith(Enchantment arg0) {
        return false;
    }

    @Override
    public EnchantmentTarget getItemTarget() {
        return null;
    }

    @Override
    public int getMaxLevel() {
        return 2;
    }

    @Override
    public String getName() {
        return "Insurance";
    }

    @Override
    public int getStartLevel() {
        return 1;
    }

    @Override
    public boolean isCursed() {
        return false;
    }

    @Override
    public boolean isTreasure() {
        return false;
    }

}

thx for helping, Magnido9

 

First, you should make sure that the enchantment does not exist before getting it. If the server reloads, enchantments are not cleared, and this would throw an error (however, most likely not the one you are experiencing)

Can you post the error in the console? That should tell us what is causing the problem.

 

This is what it says in logs when I do the command:

Code:

[10:35:08] [Server thread/INFO]: Magnido9 issued server command: /insurance
[10:35:08] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'insurance' in plugin Insurance v1
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot.jar:git-Spigot-d21162c-61e0c69]
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[spigot.jar:git-Spigot-d21162c-61e0c69]
at org.bukkit.craftbukkit.v1_12_R1.CraftServer.dispatchCommand(CraftServer.java:651) ~[spigot.jar:git-Spigot-d21162c-61e0c69]
at net.minecraft.server.v1_12_R1.PlayerConnection.handleCommand(PlayerConnection.java:1397) [spigot.jar:git-Spigot-d21162c-61e0c69]
at net.minecraft.server.v1_12_R1.PlayerConnection.a(PlayerConnection.java:1232) [spigot.jar:git-Spigot-d21162c-61e0c69]
at net.minecraft.server.v1_12_R1.PacketPlayInChat.a(PacketPlayInChat.java:45) [spigot.jar:git-Spigot-d21162c-61e0c69]
at net.minecraft.server.v1_12_R1.PacketPlayInChat.a(PacketPlayInChat.java:1) [spigot.jar:git-Spigot-d21162c-61e0c69]
at net.minecraft.server.v1_12_R1.PlayerConnectionUtils$1.run(SourceFile:13) [spigot.jar:git-Spigot-d21162c-61e0c69]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_91]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_91]
at net.minecraft.server.v1_12_R1.SystemUtils.a(SourceFile:46) [spigot.jar:git-Spigot-d21162c-61e0c69]
at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:748) [spigot.jar:git-Spigot-d21162c-61e0c69]
at net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:406) [spigot.jar:git-Spigot-d21162c-61e0c69]
at net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:679) [spigot.jar:git-Spigot-d21162c-61e0c69]
at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:577) [spigot.jar:git-Spigot-d21162c-61e0c69]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_91]
Caused by: java.lang.NullPointerException
at com.gmail.magnido9.Insurance.Insurance.onCommand(Insurance.java:56) ~[?:?]
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spigot.jar:git-Spigot-d21162c-61e0c69]
... 15 more

about the reloading,I do not reload, I always restart the server.

 

still doesnt works