Bukkit

Got this error when Vannished and typed /ha tool

18:23:18 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'ha' in plugin HawkEye v1.0.5b
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:42)
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:166)
        at org.bukkit.craftbukkit.CraftServer.dispatchCommand(CraftServer.java:378)
        at net.minecraft.server.NetServerHandler.handleCommand(NetServerHandler.java:757)
        at net.minecraft.server.NetServerHandler.chat(NetServerHandler.java:722)
        at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:715)
        at org.getspout.spout.SpoutNetServerHandler.a(SpoutNetServerHandler.java:180)
        at net.minecraft.server.Packet3Chat.a(Packet3Chat.java:33)
        at net.minecraft.server.NetworkManager.b(NetworkManager.java:226)
        at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:93)
        at org.getspout.spout.SpoutNetServerHandler.a(SpoutNetServerHandler.java:550)
        at net.minecraft.server.NetworkListenThread.a(SourceFile:108)
        at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:527)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:425)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:457)
Caused by: java.lang.NullPointerException
        at org.bukkit.craftbukkit.inventory.CraftItemStack.clone(CraftItemStack.java:215)
        at org.bukkit.craftbukkit.inventory.CraftItemStack.clone(CraftItemStack.java:13)
        at uk.co.oliwali.HawkEye.ToolManager.enableTool(ToolManager.java:46)
        at uk.co.oliwali.HawkEye.commands.ToolCommand.execute(ToolCommand.java:23)
        at uk.co.oliwali.HawkEye.commands.BaseCommand.run(BaseCommand.java:75)
        at uk.co.oliwali.HawkEye.HawkEye.onCommand(HawkEye.java:282)
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:40)
        ... 14 more