Bukkit

What version of the product are you using?
The newest Beta for 1.6.2

Do you have an error log of what happened?
2013-08-01 18:43:09 [SEVERE] Error occurred while enabling HungerGames v2.0 (Is it up to date?)
java.lang.NullPointerException
    at me.minebuilders.hg.Bound.getBlocks(Bound.java:57)
    at me.minebuilders.hg.Game.setChests(Game.java:116)
    at me.minebuilders.hg.Game.<init>(Game.java:61)
    at me.minebuilders.hg.data.Data.load(Data.java:111)
    at me.minebuilders.hg.data.Data.<init>(Data.java:29)
    at me.minebuilders.hg.HG.onEnable(HG.java:64)
    at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
    at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:457)
    at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)
    at org.bukkit.craftbukkit.v1_6_R2.CraftServer.loadPlugin(CraftServer.java:282)
    at org.bukkit.craftbukkit.v1_6_R2.CraftServer.enablePlugins(CraftServer.java:264)
    at net.minecraft.server.v1_6_R2.MinecraftServer.l(MinecraftServer.java:313)
    at net.minecraft.server.v1_6_R2.MinecraftServer.f(MinecraftServer.java:290)
    at net.minecraft.server.v1_6_R2.MinecraftServer.a(MinecraftServer.java:250)
    at net.minecraft.server.v1_6_R2.DedicatedServer.init(DedicatedServer.java:151)
    at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:391)
    at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)

I just get this error and can´t use the command /hg ingame.

This is when your world in which is your arena is not loaded.

The map is loaded and still got the error