When I run my server it says:

[17:09:11 ERROR]: Encountered an unexpected exception
java.lang.RuntimeException: java.util.zip.ZipException: incorrect header check
at org.bukkit.craftbukkit.v1_12_R1.chunkio.ChunkIOProvider.callStage1(ChunkIOProvider.java:30) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at org.bukkit.craftbukkit.v1_12_R1.chunkio.ChunkIOProvider.callStage1(ChunkIOProvider.java:1) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at org.bukkit.craftbukkit.v1_12_R1.util.AsynchronousExecutor.skipQueue(AsynchronousExecutor.java:336) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at org.bukkit.craftbukkit.v1_12_R1.util.AsynchronousExecutor.getSkipQueue(AsynchronousExecutor.java:295) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at org.bukkit.craftbukkit.v1_12_R1.chunkio.ChunkIOExecutor.syncChunkLoad(ChunkIOExecutor.java:16) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:137) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:120) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:116) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.MinecraftServer.l(MinecraftServer.java:374) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.MinecraftServer.a(MinecraftServer.java:338) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.DedicatedServer.init(DedicatedServer.java:272) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:545) [Spigot.jar:git-Spigot-5695bca-53fccdf]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_121]
Caused by: java.util.zip.ZipException: incorrect header check
at java.util.zip.InflaterInputStream.read(Unknown Source) ~[?:1.8.0_121]
at java.io.BufferedInputStream.fill(Unknown Source) ~[?:1.8.0_121]
at java.io.BufferedInputStream.read(Unknown Source) ~[?:1.8.0_121]
at java.io.DataInputStream.readByte(Unknown Source) ~[?:1.8.0_121]
at net.minecraft.server.v1_12_R1.NBTCompressedStreamTools.a(NBTCompressedStreamTools.java:75) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.NBTCompressedStreamTools.a(NBTCompressedStreamTools.java:53) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.NBTCompressedStreamTools.a(NBTCompressedStreamTools.java:43) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.RegionFileCache.d(RegionFileCache.java:87) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.ChunkRegionLoader.loadChunk(ChunkRegionLoader.java:62) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at org.bukkit.craftbukkit.v1_12_R1.chunkio.ChunkIOProvider.callStage1(ChunkIOProvider.java:21) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
... 12 more
[17:09:11 ERROR]: Cause of unexpected exception was
java.util.zip.ZipException: incorrect header check
at java.util.zip.InflaterInputStream.read(Unknown Source) ~[?:1.8.0_121]
at java.io.BufferedInputStream.fill(Unknown Source) ~[?:1.8.0_121]
at java.io.BufferedInputStream.read(Unknown Source) ~[?:1.8.0_121]
at java.io.DataInputStream.readByte(Unknown Source) ~[?:1.8.0_121]
at net.minecraft.server.v1_12_R1.NBTCompressedStreamTools.a(NBTCompressedStreamTools.java:75) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.NBTCompressedStreamTools.a(NBTCompressedStreamTools.java:53) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.NBTCompressedStreamTools.a(NBTCompressedStreamTools.java:43) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.RegionFileCache.d(RegionFileCache.java:87) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.ChunkRegionLoader.loadChunk(ChunkRegionLoader.java:62) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at org.bukkit.craftbukkit.v1_12_R1.chunkio.ChunkIOProvider.callStage1(ChunkIOProvider.java:21) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at org.bukkit.craftbukkit.v1_12_R1.chunkio.ChunkIOProvider.callStage1(ChunkIOProvider.java:1) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at org.bukkit.craftbukkit.v1_12_R1.util.AsynchronousExecutor.skipQueue(AsynchronousExecutor.java:336) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at org.bukkit.craftbukkit.v1_12_R1.util.AsynchronousExecutor.getSkipQueue(AsynchronousExecutor.java:295) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at org.bukkit.craftbukkit.v1_12_R1.chunkio.ChunkIOExecutor.syncChunkLoad(ChunkIOExecutor.java:16) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:137) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:120) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.ChunkProviderServer.getChunkAt(ChunkProviderServer.java:116) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.MinecraftServer.l(MinecraftServer.java:374) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.MinecraftServer.a(MinecraftServer.java:338) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.DedicatedServer.init(DedicatedServer.java:272) ~[Spigot.jar:git-Spigot-5695bca-53fccdf]
at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:545) [Spigot.jar:git-Spigot-5695bca-53fccdf]
at java.lang.Thread.run(Unknown Source)[?:1.8.0_121]

This is the code for my plugin:

main.java:

package com.RedstoneSurvivor.SpigotPlugin;import org.bukkit.Bukkit;
import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.World;
import org.bukkit.block.Block;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.inventory.Inventory;
import org.bukkit.inventory.ItemStack;
import org.bukkit.plugin.PluginManager;
import org.bukkit.plugin.java.JavaPlugin;public class Main extends JavaPlugin {@Override
{{ public void onEnable() {}}

{{ getLogger().info("Custom plugin has been enabled");}}
{{ PluginManager pm = getServer().getPluginManager();}}
{{ Listener listener = new Listener(this);}}
{{ pm.registerEvents(listener, this);}}

{{ }}}

{{ @Override}}
{{ public void onDisable() {}}

{{ getLogger().info("Custom plugin has been disabled");}}

{{ }}}

{{ @SuppressWarnings("deprecation")}}
{{ public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {}}

{{ ItemStack item = new ItemSmith().buildWeapon1(1);}}
{{ Player player =(Player) sender;}}

{{ if (sender instanceof Player) {}}Inventory inv = player.getInventory();

{{ String lowerCmd = cmd.getName().toLowerCase();}}

{{ switch (lowerCmd) {}}

{{ case "glow":}}

{{ Location blockLoc1 = player.getLocation().add(0, 2, 0);}}

{{ if (blockLoc1.getBlock().getType().equals(Material.AIR)) {}}

{{ blockLoc1.getBlock().setType(Material.GLOWSTONE);}}
{{ return true;}}

{{ } else {}}

{{ player.sendMessage("You must have air above you to use this command!");}}
{{ return true;}}

{{ }}}

{{ case "jungle":}}

{{ Location blockLoc2 = player.getLocation().add(2, 0, 0);}}

{{ if (blockLoc2.getBlock().getType().equals(Material.AIR)) {}}

{{ Block jungleBlock = blockLoc2.getBlock();}}
{{ jungleBlock.setType(Material.LOG);}}
{{ jungleBlock.setData((byte) 3);}}
{{ return true;}}

{{ } else {}}

{{ player.sendMessage("You must have air to your side to use this command!");}}
{{ return true;}}

{{ }}}

{{ case "netherport":}}

{{ World nether = Bukkit.getServer().getWorld("world_nether");}}
{{ Location loc1 = new Location(nether, -29, 52, -29);}}

{{ player.teleport(loc1);}}
{{ return true;}}

{{ case "worldport":}}

{{ World world = Bukkit.getServer().getWorld("world");}}
{{ Location loc2 = new Location(world, -249, 68, 261);}}

{{ player.teleport(loc2);}}
{{ return true;}}

{{ case "givesword":}}

{{ int length = args.length;}}

{{ switch (length) {}}

{{ case 1:}}
{{ if ( args[0].equalsIgnoreCase("2") ) {}}
{{ new ItemSmith().buildWeapon1(1);}}
{{ inv.addItem(item);}}
{{ inv.addItem(item);}}
{{ return true;}}
{{ }}}
{{ case 0:}}
{{ new ItemSmith().buildWeapon1(1);}}
{{ inv.addItem(item);}}
{{ player.sendMessage("Your command was recognized");}}
{{ default:}}
{{ player.sendMessage("Your command was not recognized");}}
{{ return true;}}

{{ }}}

{{ }}}

{{ }}}

{{ player.sendMessage("Your command was not recognized");}}
{{ return true;}}

{{ }}}

}

Listener.java:

package com.RedstoneSurvivor.SpigotPlugin;import org.bukkit.Location;
import org.bukkit.entity.Entity;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.entity.EntityDamageByEntityEvent;
import org.bukkit.event.player.PlayerJoinEvent;
import org.bukkit.inventory.ItemStack;public class Listener implements org.bukkit.event.Listener {//Constructor
{{ public Listener(Main plugin) {}}

{{ }}}

{{ //EventHandler}}
{{ @EventHandler}}
{{ public void onPlayerJoin(PlayerJoinEvent event) {}}

{{ Player player =(Player) event.getPlayer();}}

{{ event.getPlayer().sendMessage("Welcome to RedstoneFace");}}

{{ ItemStack item2 = new ItemSmith().buildWeapon2(1);}}

{{ player.getInventory().addItem(item2);}}

{{ }}}

{{ @EventHandler}}
{{ public void onPlayerDamage(EntityDamageByEntityEvent event) {}}

{{ Entity entity =event.getEntity();}}

{{ if ( entity instanceof Player) {}}

{{ Player player = (Player) entity;}}
{{ Location playerLoc = player.getLocation();}}
{{ int min = -10;}}
{{ int max = 10;}}
{{ int range = max - min;}}
{{ Location loc = playerLoc.add((int)(Math.random()*range)+min, 10, (int)(Math.random()*range)+min);}}

{{ player.teleport(loc);}}

{{ }}}

{{ }}}

}

ItemSmith.java:

package com.RedstoneSurvivor.SpigotPlugin;import java.util.ArrayList;import org.bukkit.ChatColor;
import org.bukkit.Material;
import org.bukkit.inventory.ItemFlag;
import org.bukkit.inventory.ItemStack;
import org.bukkit.inventory.meta.ItemMeta;public class ItemSmith {public ItemStack makeItem1(Material m, String name, String desc, int amount) {

{{ ItemStack item = new ItemStack (m, 1);}}

{{ //Creates the item's meta data (name, lore/description text, etc.)}}
{{ ItemMeta im = item.getItemMeta();}}
{{ im.setDisplayName(name);}}
{{ //Creates the lore}}
{{ ArrayList<String> lore =new ArrayList<String>(); }}
{{ lore.add(desc);}}
{{ im.setLore(lore);}}
{{ //Hides the vanilla Minecraft tooltip text}}
{{ im.addItemFlags(ItemFlag.HIDE_ENCHANTS);}}
{{ im.addItemFlags(ItemFlag.HIDE_ATTRIBUTES);}}
{{ //Sets theitem's meta data to the custom "im" meta data}}
{{ item.setItemMeta(im);}}

{{ return item;}}

{{ }}}
{{ public ItemStack buildWeapon1(int amount) {}}

{{ Material m = Material.GOLD_SWORD;}}
{{ String name = (ChatColor.GOLD + "" + ChatColor.BOLD + "Sword of King Midas");}}
{{ String desc = (ChatColor.DARK_GRAY + "" + ChatColor.ITALIC + "The golden sword of King Midas!");}}

{{ return makeItem1(m, name, desc, amount);}}

{{ }}}
{{ public ItemStack buildWeapon2(int amount) {}}

{{ Material m = Material.PAPER;}}
{{ String name = (ChatColor.GOLD + "Welcome to RedstoneFACE");}}
{{ String desc = (ChatColor.DARK_GRAY + "Don't forget to read the rules in the House of Rules!");}}

{{ return makeItem1(m, name, desc, amount);}}

{{ }}}

}

Please help.