NPE Error

When I move, I get this error:

Code:

Could not pass event PlayerMoveEvent to RepalceCommandBlocks v1.0
org.bukkit.event.EventException: null
        at us.Myles.PWP.TransparentListeners.PerWorldPluginLoader$1.execute(PerWorldPluginLoader.java:122) ~[?:?]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[server.jar:git-Spigot-f39a89e-4633e6c]
        at us.Myles.PWP.TransparentListeners.PWPRegisteredListener.callEvent(PWPRegisteredListener.java:30) ~[?:?]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:529) ~[server.jar:git-Spigot-f39a89e-4633e6c]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:514) ~[server.jar:git-Spigot-f39a89e-4633e6c]
        at net.minecraft.server.v1_15_R1.PlayerConnection.a(PlayerConnection.java:998) ~[server.jar:git-Spigot-f39a89e-4633e6c]
        at net.minecraft.server.v1_15_R1.PacketPlayInFlying.a(SourceFile:122) ~[server.jar:git-Spigot-f39a89e-4633e6c]
        at net.minecraft.server.v1_15_R1.PacketPlayInFlying$PacketPlayInPosition.a(SourceFile:56) ~[server.jar:git-Spigot-f39a89e-4633e6c]
        at net.minecraft.server.v1_15_R1.PlayerConnectionUtils.lambda$0(PlayerConnectionUtils.java:19) ~[server.jar:git-Spigot-f39a89e-4633e6c]
        at net.minecraft.server.v1_15_R1.TickTask.run(SourceFile:18) [server.jar:git-Spigot-f39a89e-4633e6c]
        at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.executeTask(SourceFile:144) [server.jar:git-Spigot-f39a89e-4633e6c]
        at net.minecraft.server.v1_15_R1.IAsyncTaskHandlerReentrant.executeTask(SourceFile:23) [server.jar:git-Spigot-f39a89e-4633e6c]
        at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.executeNext(SourceFile:118) [server.jar:git-Spigot-f39a89e-4633e6c]
        at net.minecraft.server.v1_15_R1.MinecraftServer.aZ(MinecraftServer.java:917) [server.jar:git-Spigot-f39a89e-4633e6c]
        at net.minecraft.server.v1_15_R1.MinecraftServer.executeNext(MinecraftServer.java:910) [server.jar:git-Spigot-f39a89e-4633e6c]
        at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.executeAll(SourceFile:103) [server.jar:git-Spigot-f39a89e-4633e6c]
        at net.minecraft.server.v1_15_R1.MinecraftServer.sleepForTick(MinecraftServer.java:893) [server.jar:git-Spigot-f39a89e-4633e6c]
        at net.minecraft.server.v1_15_R1.MinecraftServer.run(MinecraftServer.java:827) [server.jar:git-Spigot-f39a89e-4633e6c]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_221]

I have PerWorldPlugins with the same plugin, but I doubt it has an issue with it.
PlayerListeners.java:

Code:

package xp10d3.replace.corelia;
import java.text.SimpleDateFormat;
import org.bukkit.configuration.ConfigurationSection;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerMoveEvent;
import com.mysql.fabric.xmlrpc.base.Data;
public class PlayerListeners implements Listener {
    private Core core;
  
    @EventHandler
    public void savePlayerLocation(PlayerMoveEvent event) {
        Player player = event.getPlayer();
        core.getConfig().set(player.getUniqueId().toString() + ".lastlocation.x", player.getLocation().getX());
        core.getConfig().set(player.getUniqueId().toString() + ".lastlocation.y", player.getLocation().getY());
        core.getConfig().set(player.getUniqueId().toString() + ".lastlocation.z", player.getLocation().getZ());
        core.getConfig().set(player.getUniqueId().toString() + ".lastlocation.world", player.getLocation().getWorld().getName());
        core.saveConfig();
    }
  
    @EventHandler
    public void checkLocation(PlayerMoveEvent event) {
      
        Player player = event.getPlayer();
        int locationX = core.getConfig().getInt(player.getUniqueId().toString() + ".lastlocation.x");
        int locationY = core.getConfig().getInt(player.getUniqueId().toString() + ".lastlocation.y");
        int locationZ = core.getConfig().getInt(player.getUniqueId().toString() + ".lastlocation.z");
        String locationWorld = core.getConfig().getString(player.getUniqueId().toString() + ".lastlocation.world");
      
        ConfigurationSection command = core.getConfig().getConfigurationSection("command.commands");
        for (String key : command.getKeys(false)) {
            int x = core.getConfig().getInt("command.commands." + key + ".x");
            int y = core.getConfig().getInt("command.commands." + key + ".y");
            int z = core.getConfig().getInt("command.commands." + key + ".z");
            String world = core.getConfig().getString("command.commands." + key + ".world");
            if (x == locationX && y == locationY && z == locationZ && world == locationWorld) {
                core.getServer().dispatchCommand(core.getServer().getConsoleSender(), key.replace("%player%", player.getName()));
                Data now = new Data();
                SimpleDateFormat format = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
              
                core.logFile("[" + format.format(now) + "]" + " Dispatched command " + "'" + key + "'" + " at X value " + locationX + " Y value " + locationY + " Z value " + locationZ + " in world " + locationWorld + ".");
            }
        }
    }
}

How do I fix this error?

Config:

Code:

command:
  commands:
    effect give @p slowness 500 50:
      x: 50
      y: 75
      z: 3
      world: world

I don't know the exact numbers for the x, y, and z values but this is pretty much it.