Why is my Scoreboard not Working?

I watched tons of Videos "How to write an own Plugin" and almost lerned enogh to programm my first little Plugin, but now i´m trying to use a Scoreboard but I´m not get it working......
I´m using Windows 10 x64bit, java version 1.8.0 and the craftbukkit-1.6.4-R2.0.jar

Main class:

Code:

package Minecraft.aotbt.ian;

import [...]


public class Projekt01 extends JavaPlugin {
 
 
 
    @Override
    public void onEnable() {
        this.getLogger().info("Das Plugin ist aktiviert #DankeFelix");
     
        Config();
     
     
        new EventListener(this);
    }
    public void onDisable() {
        this.getLogger().info("#Ianistsüß  XDD");
     
    }
 
    private void Config() {
        this.reloadConfig();
        this.getConfig().addDefault("Punkte.Hoellenhunde", 0);
        this.getConfig().addDefault("Punkte.Pinguine", 0 );
        this.getConfig().addDefault("Meilenstein.normal.block.block", false);
     
        this.getConfig().addDefault("Meilenstein.normal.block.punkte", 3);
     
        this.getConfig().options().copyDefaults(true);
        this.saveConfig();
        System.out.println("Config Datei wurde geladen");
    }
 
    void displayScoreboard(Player p) {
        Scoreboard board = Bukkit.getScoreboardManager().getNewScoreboard();
        Objective obj = board.registerNewObjective("Punkte", "dummy");
     
        obj.setDisplaySlot(DisplaySlot.SIDEBAR);
        obj.setDisplayName(ChatColor.LIGHT_PURPLE +"Punkte:");
     
        obj.getScore(Bukkit.getOfflinePlayer( ChatColor.GOLD+"Hoellenhunde")).setScore(4);
        obj.getScore(Bukkit.getOfflinePlayer(ChatColor.RED + Integer.toString( this.getConfig().getInt("Punkte.Hoellenhunde")))).setScore(3);
        obj.getScore(Bukkit.getOfflinePlayer("==============")).setScore(2);
        obj.getScore(Bukkit.getOfflinePlayer(ChatColor.GOLD +"Pinguine")).setScore(1);
        obj.getScore(Bukkit.getOfflinePlayer(ChatColor.RED + Integer.toString( this.getConfig().getInt("Punkte.pinguine")) +" ")).setScore(0);
     
     
        p.setScoreboard(board);
    }
@Override
public boolean onCommand(Command sender, Command cmd, String commandLabel, String[] args){
[.....]
   }
}

Event Listener class:

Code:

package Minecraft.aotbt.ian;

import [...]


public class EventListener implements Listener {
 
    Projekt01 Pr01 = new Projekt01();
    int sched;
    public EventListener(Projekt01 Pr) {
    Pr.getServer().getPluginManager().registerEvents(this, Pr);
 
    }
    @EventHandler
    public void OnJoin(PlayerJoinEvent e) {
        Pr01.displayScoreboard(e.getPlayer());
     
        if(!Bukkit.getScheduler().isCurrentlyRunning(sched)) {
            sched = Bukkit.getScheduler().scheduleSyncRepeatingTask(Pr01, new Runnable(){
                @Override
                public void run() {
                    Pr01.displayScoreboard(e.getPlayer());
                }
            }, 20, 20);
        }
    }
 

}

I can Join the Server but everytime I do, I get an error :/

Code:

19:39:06 [INFORMATION] Ver_Flix[/127.0.0.1:53262] logged in with entity id 341 at ([world] -79.9227217467842, 100.30018066426732, 234.5465218142107)
19:39:06 [SCHWERWIEGEND] Could not pass event PlayerJoinEvent to Projekt01 v1.0
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:427)
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:477)
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:462)
        at net.minecraft.server.v1_6_R3.PlayerList.c(PlayerList.java:207)
        at net.minecraft.server.v1_6_R3.PlayerList.a(PlayerList.java:103)
        at net.minecraft.server.v1_6_R3.PendingConnection.e(PendingConnection.java:132)
        at net.minecraft.server.v1_6_R3.PendingConnection.d(PendingConnection.java:43)
        at net.minecraft.server.v1_6_R3.DedicatedServerConnectionThread.a(DedicatedServerConnectionThread.java:41)
        at net.minecraft.server.v1_6_R3.DedicatedServerConnection.b(SourceFile:29)
        at net.minecraft.server.v1_6_R3.MinecraftServer.t(MinecraftServer.java:592)
        at net.minecraft.server.v1_6_R3.DedicatedServer.t(DedicatedServer.java:227)
        at net.minecraft.server.v1_6_R3.MinecraftServer.s(MinecraftServer.java:488)
        at net.minecraft.server.v1_6_R3.MinecraftServer.run(MinecraftServer.java:421)
        at net.minecraft.server.v1_6_R3.ThreadServerApplication.run(SourceFile:583)
Caused by: java.lang.IllegalArgumentException: File cannot be null
        at org.apache.commons.lang.Validate.notNull(Validate.java:203)
        at org.bukkit.configuration.file.YamlConfiguration.loadConfiguration(YamlConfiguration.java:170)
        at org.bukkit.plugin.java.JavaPlugin.reloadConfig(JavaPlugin.java:117)
        at org.bukkit.plugin.java.JavaPlugin.getConfig(JavaPlugin.java:111)
        at Minecraft.aotbt.ian.Projekt01.displayScoreboard(Projekt01.java:63)
        at Minecraft.aotbt.ian.EventListener.OnJoin(EventListener.java:30)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425)
        ... 14 more

 

In your EventListener constructor define Pr01 as the Project01 that you pass to the constructor. So

Code:

Pr01 = Pr;

and do not define Pr01 as a new Project01