2012-09-04 19:50:25 [SEVERE] Error occurred while enabling Factions v1.6.9.1 (Is it up to date?)

java.lang.NoClassDefFoundError: org/bukkit/craftbukkit/libs/com/google/gson/reflect/TypeToken

    at java.lang.ClassLoader.defineClass1(Native Method)

    at java.lang.ClassLoader.defineClass(Unknown Source)

    at java.security.SecureClassLoader.defineClass(Unknown Source)

    at java.net.URLClassLoader.defineClass(Unknown Source)

    at java.net.URLClassLoader.access$100(Unknown Source)

    at java.net.URLClassLoader$1.run(Unknown Source)

    at java.net.URLClassLoader$1.run(Unknown Source)

    at java.security.AccessController.doPrivileged(Native Method)

    at java.net.URLClassLoader.findClass(Unknown Source)

    at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:44)

    at org.bukkit.plugin.java.JavaPluginLoader.getClassByName(JavaPluginLoader.java:239)

    at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:40)

    at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:29)

    at java.lang.ClassLoader.loadClass(Unknown Source)

    at java.lang.ClassLoader.loadClass(Unknown Source)

    at com.massivecraft.factions.P.getGsonBuilder(P.java:128)

    at com.massivecraft.factions.zcore.MPlugin.preEnable(MPlugin.java:68)

    at com.massivecraft.factions.P.onEnable(P.java:82)

    at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)

    at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:365)

    at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)

    at org.bukkit.craftbukkit.CraftServer.loadPlugin(CraftServer.java:265)

    at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:247)

    at org.bukkit.craftbukkit.CraftServer.reload(CraftServer.java:567)

    at org.bukkit.Bukkit.reload(Bukkit.java:183)

    at org.bukkit.command.defaults.ReloadCommand.execute(ReloadCommand.java:21)

    at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:168)

    at org.bukkit.craftbukkit.CraftServer.dispatchCommand(CraftServer.java:492)

    at net.minecraft.server.NetServerHandler.handleCommand(NetServerHandler.java:878)

    at net.minecraft.server.NetServerHandler.chat(NetServerHandler.java:825)

    at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:807)

    at net.minecraft.server.Packet3Chat.handle(Packet3Chat.java:44)

    at net.minecraft.server.NetworkManager.b(NetworkManager.java:276)

    at net.minecraft.server.NetServerHandler.d(NetServerHandler.java:109)

    at net.minecraft.server.ServerConnection.b(SourceFile:35)

    at net.minecraft.server.DedicatedServerConnection.b(SourceFile:30)

    at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:581)

    at net.minecraft.server.DedicatedServer.q(DedicatedServer.java:212)

    at net.minecraft.server.MinecraftServer.p(MinecraftServer.java:474)

    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:406)

    at net.minecraft.server.ThreadServerApplication.run(SourceFile:539)

Caused by: java.lang.ClassNotFoundException: org.bukkit.craftbukkit.libs.com.google.gson.reflect.TypeToken

    at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:34)

    at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:29)

    at java.lang.ClassLoader.loadClass(Unknown Source)

    at java.lang.ClassLoader.loadClass(Unknown Source)

    ... 41 more