Aide Plugin Faction Minecraft

Bonjour,
J'ai installé le plugin Faction sur mon serveur MInecraft. Quand je suis en jeu je tape n'importe qu'elle commande de faction et rien ne se passe. Voici mes logs: 2012-05-11 22:30:18 [INFO] [Factions v1.6.7] Creating default: plugins/Factions/conf.json
2012-05-11 22:30:18 [SEVERE] Error occurred while enabling Factions v1.6.7 (Is it up to date?)
java.lang.AssertionError
at com.google.gson.internal.bind.TypeAdapters$EnumTypeAdapter.<init>(TypeAdapters.java:686)
at com.google.gson.internal.bind.TypeAdapters$24.create(TypeAdapters.java:715)
at com.google.gson.Gson.getAdapter(Gson.java:353)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory.create(CollectionTypeAdapterFactory.java:52)
at com.google.gson.Gson.getAdapter(Gson.java:353)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.<init>(ReflectiveTypeAdapterFactory.java:82)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:81)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:118)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:72)
at com.google.gson.Gson.getAdapter(Gson.java:353)
at com.google.gson.Gson.toJson(Gson.java:538)
at com.google.gson.Gson.toJson(Gson.java:525)
at com.google.gson.Gson.toJson(Gson.java:480)
at com.google.gson.Gson.toJson(Gson.java:460)
at com.massivecraft.factions.zcore.util.Persist.save(Persist.java:116)
at com.massivecraft.factions.zcore.util.Persist.loadOrSaveDefault(Persist.java:80)
at com.massivecraft.factions.zcore.util.Persist.loadOrSaveDefault(Persist.java:72)
at com.massivecraft.factions.Conf.load(Conf.java:352)
at com.massivecraft.factions.P.onEnable(P.java:83)
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:215)
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:336)
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)
at org.bukkit.craftbukkit.CraftServer.loadPlugin(CraftServer.java:256)
at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:238)
at net.minecraft.server.MinecraftServer.t(MinecraftServer.java:375)
at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:362)
at net.minecraft.server.MinecraftServer.init(MinecraftServer.java:191)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:426)
at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)
2012-05-11 22:30:18 [INFO] [Lockette] Enabled link to plugin Factions for Groups, version 1.6.7

Merci