Bukkit

What steps will reproduce the problem?
run command /pvp region add regionName

What is the expected output?
added region on region.yml i think, first use...

What do you see instead?
an internal error occurred while attempting to perform this command

What version are you using?
3.0.0

Do you have an error log of what happened?
2013-01-13 15:44:43 [INFO] clavats issued server command: /pvp region add crimsoncity
2013-01-13 15:44:43 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'pvp' in plugin PvPToggle v3.0.0
    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46)
    at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:186)
    at org.bukkit.craftbukkit.CraftServer.dispatchCommand(CraftServer.java:502)
    at net.minecraft.server.NetServerHandler.handleCommand(NetServerHandler.java:985)
    at net.minecraft.server.NetServerHandler.chat(NetServerHandler.java:903)
    at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:858)
    at net.minecraft.server.Packet3Chat.handle(Packet3Chat.java:44)
    at net.minecraft.server.NetworkManager.b(NetworkManager.java:290)
    at net.minecraft.server.NetServerHandler.d(NetServerHandler.java:113)
    at net.minecraft.server.ServerConnection.b(SourceFile:39)
    at net.minecraft.server.DedicatedServerConnection.b(SourceFile:30)
    at net.minecraft.server.MinecraftServer.r(MinecraftServer.java:595)
    at net.minecraft.server.DedicatedServer.r(DedicatedServer.java:222)
    at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:493)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:426)
    at net.minecraft.server.ThreadServerApplication.run(SourceFile:856)
Caused by: java.lang.NullPointerException
    at com.sleelin.pvptoggle.handlers.RegionHandler.addRegion(RegionHandler.java:83)
    at com.sleelin.pvptoggle.commands.Region.addRegion(Region.java:73)
    at com.sleelin.pvptoggle.commands.Region.processCommand(Region.java:33)
    at com.sleelin.pvptoggle.PvPCommand.exec(PvPCommand.java:38)
    at com.sleelin.pvptoggle.handlers.CommandHandler.onCommand(CommandHandler.java:44)
    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
    ... 15 more

Please provide any additional information below:
i have added pvp flag on my region, and i would like to force pvp on when players comming into the region.

I have the same issue

Wait I just solved it, You have to turn world Guard integration on