Hi, I'm doing a plugin that saves the player's kills to the config and I get such an error: Console: Code: [19:18:32 ERROR]: null org.bukkit.command.CommandException: Unhandled exception executing command 'zabojstwa' in plugin BombaCraft v1.0 at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[servert.jar:git-Spigot-db6de12-18fbb24] at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[servert.jar:git-Spigot-db6de12-18fbb24] at org.bukkit.craftbukkit.v1_8_R3.CraftServer.dispatchCommand(CraftServer.java:641) ~[servert.jar:git-Spigot-db6de12-18fbb24] at net.minecraft.server.v1_8_R3.PlayerConnection.handleCommand(PlayerConnection.java:1162) [servert.jar:git-Spigot-db6de12-18fbb24] at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:997) [servert.jar:git-Spigot-db6de12-18fbb24] at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(PacketPlayInChat.java:45) [servert.jar:git-Spigot-db6de12-18fbb24] at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(PacketPlayInChat.java:1) [servert.jar:git-Spigot-db6de12-18fbb24] at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [servert.jar:git-Spigot-db6de12-18fbb24] at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515) [?:?] at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) [?:?] at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [servert.jar:git-Spigot-db6de12-18fbb24] at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:715) [servert.jar:git-Spigot-db6de12-18fbb24] at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:374) [servert.jar:git-Spigot-db6de12-18fbb24] at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:654) [servert.jar:git-Spigot-db6de12-18fbb24] at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:557) [servert.jar:git-Spigot-db6de12-18fbb24] at java.base/java.lang.Thread.run(Thread.java:829) [?:?] Caused by: java.lang.NullPointerException at pl.jedzius.commands.Zabojstwa.onCommand(Zabojstwa.java:29) ~[?:?] at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[servert.jar:git-Spigot-db6de12-18fbb24] ... 15 more Zabojstwa.java Code: Main plugin; @Override public boolean onCommand(CommandSender sender, Command command, String label, String[] args) { Player player = (Player) sender; Map<String, Integer> kills = new HashMap<String, Integer>(); for(OfflinePlayer p : Bukkit.getOfflinePlayers()) { UUID uuid = p.getUniqueId(); kills.put(p.getName(), plugin.getConfig().getInt(uuid + ".Kills")); } AtomicInteger counter = new AtomicInteger(); kills.entrySet() .stream() .sorted(Map.Entry.comparingByValue(Comparator.reverseOrder())) .limit(10) .forEach(e -> {String num = counter.incrementAndGet() + ". "; player.sendMessage(ColorUtil.fixColor("&7" + num + "&e" + e.getKey() + "&7: &e" + e.getValue())); }); return false; } What to do to fix this error? Thanks in advance for your help