Bukkit

What steps will reproduce the problem?
1.Typing in the command
2.
3.

What is the expected output? What do you see instead?
/

What version of the product are you using?
Latest

Do you have an error log of what happened?
Yes, well this pops up in my bukkit cmd.exe thingy:
19:21:43 [INFO] TedJeurs issued server command: /npcskin http://minecraftskins.i
nfo/Modernsoldier.png
19:21:43 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'npcs
kin' in plugin CitizenSkins v2.0.41.73
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46)
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:18
6)
        at org.bukkit.craftbukkit.v1_4_6.CraftServer.dispatchCommand(CraftServer
.java:510)
        at net.minecraft.server.v1_4_6.PlayerConnection.handleCommand(PlayerConn
ection.java:980)
        at net.minecraft.server.v1_4_6.PlayerConnection.chat(PlayerConnection.ja
va:898)
        at net.minecraft.server.v1_4_6.PlayerConnection.a(PlayerConnection.java:
853)
        at org.getspout.spout.SpoutPlayerConnection.a(SpoutPlayerConnection.java
:121)
        at net.minecraft.server.v1_4_6.Packet3Chat.handle(Packet3Chat.java:44)
        at net.minecraft.server.v1_4_6.NetworkManager.b(NetworkManager.java:290)

        at net.minecraft.server.v1_4_6.PlayerConnection.d(PlayerConnection.java:
112)
        at org.getspout.spout.SpoutPlayerConnection.d(SpoutPlayerConnection.java
:196)
        at net.minecraft.server.v1_4_6.ServerConnection.b(SourceFile:39)
        at net.minecraft.server.v1_4_6.DedicatedServerConnection.b(SourceFile:30
)
        at net.minecraft.server.v1_4_6.MinecraftServer.r(MinecraftServer.java:59
8)
        at net.minecraft.server.v1_4_6.DedicatedServer.r(DedicatedServer.java:22
4)
        at net.minecraft.server.v1_4_6.MinecraftServer.q(MinecraftServer.java:49
4)
        at net.minecraft.server.v1_4_6.MinecraftServer.run(MinecraftServer.java:
427)
        at net.minecraft.server.v1_4_6.ThreadServerApplication.run(SourceFile:84
9)
Caused by: java.lang.IndexOutOfBoundsException: Index: 0
        at java.util.Collections$EmptyList.get(Unknown Source)
        at com.citizenskins.core.commands.CommandNpcSkin.onCommand(CommandNpcSki
n.java:30)
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
        ... 17 more

Please provide any additional information below.
Whenever I fill in " /npcskin http://minecraftskins.info/Modernsoldier.png " it says; an internal error has occured, please help?
Also i've got a question, what is meant with npcuid?