2013-09-13 08:28:16 [INFO] KillerRyan13 issued server command: /sw start
2013-09-13 08:28:16 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'sw' in plugin SkyWars v1.0-SNAPSHOT
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46)
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:192)
	at org.bukkit.craftbukkit.v1_6_R2.CraftServer.dispatchCommand(CraftServer.java:527)
	at net.minecraft.server.v1_6_R2.PlayerConnection.handleCommand(PlayerConnection.java:979)
	at net.minecraft.server.v1_6_R2.PlayerConnection.chat(PlayerConnection.java:890)
	at net.minecraft.server.v1_6_R2.PlayerConnection.a(PlayerConnection.java:837)
	at net.minecraft.server.v1_6_R2.Packet3Chat.handle(SourceFile:49)
	at org.spigotmc.netty.NettyNetworkManager.b(NettyNetworkManager.java:230)
	at net.minecraft.server.v1_6_R2.PlayerConnection.e(PlayerConnection.java:116)
	at net.minecraft.server.v1_6_R2.ServerConnection.b(SourceFile:37)
	at org.spigotmc.netty.NettyServerConnection.b(NettyServerConnection.java:125)
	at net.minecraft.server.v1_6_R2.MinecraftServer.t(MinecraftServer.java:592)
	at net.minecraft.server.v1_6_R2.DedicatedServer.t(DedicatedServer.java:239)
	at net.minecraft.server.v1_6_R2.MinecraftServer.s(MinecraftServer.java:481)
	at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:413)
	at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)
Caused by: java.lang.NullPointerException
	at vc.pvp.skywars.commands.StartCommand.onCommand(StartCommand.java:20)
	at vc.pvp.skywars.commands.MainCommand.onCommand(MainCommand.java:48)
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
	... 15 more

also, this :


2013-09-12 13:31:22 [SEVERE] Could not pass event PlayerInteractEvent to SkyWars v1.0-SNAPSHOT
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.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:30)
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:478)
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:463)
	at org.bukkit.craftbukkit.v1_6_R2.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:207)
	at net.minecraft.server.v1_6_R2.PlayerInteractManager.interact(PlayerInteractManager.java:374)
	at net.minecraft.server.v1_6_R2.PlayerConnection.a(PlayerConnection.java:628)
	at net.minecraft.server.v1_6_R2.Packet15Place.handle(SourceFile:58)
	at org.spigotmc.netty.NettyNetworkManager.b(NettyNetworkManager.java:230)
	at net.minecraft.server.v1_6_R2.PlayerConnection.e(PlayerConnection.java:116)
	at net.minecraft.server.v1_6_R2.ServerConnection.b(SourceFile:37)
	at org.spigotmc.netty.NettyServerConnection.b(NettyServerConnection.java:125)
	at net.minecraft.server.v1_6_R2.MinecraftServer.t(MinecraftServer.java:592)
	at net.minecraft.server.v1_6_R2.DedicatedServer.t(DedicatedServer.java:239)
	at net.minecraft.server.v1_6_R2.MinecraftServer.s(MinecraftServer.java:481)
	at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:413)
	at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)
Caused by: java.lang.NullPointerException
	at vc.pvp.skywars.listeners.PlayerListener.onPlayerInteract(PlayerListener.java:64)
	at sun.reflect.GeneratedMethodAccessor157.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425)
	... 17 more