Помогите Как совместить RPGItems и Citizens2?

При попытке поставить вещь из rpgitem в инвентарь торговца и перезаходе на сервер выдаёт ошибку
RPGItems (3.1) ItemManager.load
java.lang.NullPointerException
at think.rpgitems.item.RPGItem.getMetadata(RPGItem.java:363)
at think.rpgitems.item.RPGItem.updateItem(RPGItem.java:375)
at think.rpgitems.item.RPGItem.rebuild(RPGItem.java:351)
at think.rpgitems.item.RPGItem.<init>(RPGItem.java:204)
at think.rpgitems.item.ItemManager.load(ItemManager.java:77)
at think.rpgitems.Plugin.onEnable(Plugin.java:113)
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_5_R3.CraftServer.loadPlugin(CraftServer.java:282)
at org.bukkit.craftbukkit.v1_5_R3.CraftServer.enablePlugins(CraftServer.java:264)
at org.bukkit.craftbukkit.v1_5_R3.CraftServer.reload(CraftServer.java:605)
at org.bukkit.Bukkit.reload(Bukkit.java:185)
at org.bukkit.command.defaults.ReloadCommand.execute(ReloadCommand.java:23)
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:189)
at org.bukkit.craftbukkit.v1_5_R3.CraftServer.dispatchCommand(CraftServer.java:523)
at net.minecraft.server.v1_5_R3.PlayerConnection.handleCommand(PlayerConnection.java:965)
at net.minecraft.server.v1_5_R3.PlayerConnection.chat(PlayerConnection.java:883)
at net.minecraft.server.v1_5_R3.PlayerConnection.a(PlayerConnection.java:840)
at net.minecraft.server.v1_5_R3.Packet3Chat.handle(Packet3Chat.java:44)
at net.minecraft.server.v1_5_R3.NetworkManager.b(NetworkManager.java:292)
at net.minecraft.server.v1_5_R3.PlayerConnection.d(PlayerConnection.java:109)
at net.minecraft.server.v1_5_R3.ServerConnection.b(SourceFile:35)
at net.minecraft.server.v1_5_R3.DedicatedServerConnection.b(SourceFile:30)
at net.minecraft.server.v1_5_R3.MinecraftServer.r(MinecraftServer.java:581)
at net.minecraft.server.v1_5_R3.DedicatedServer.r(DedicatedServer.java:226)
at net.minecraft.server.v1_5_R3.MinecraftServer.q(MinecraftServer.java:477)
at net.minecraft.server.v1_5_R3.MinecraftServer.run(MinecraftServer.java:410)
at net.minecraft.server.v1_5_R3.ThreadServerApplication.run(SourceFile:573)