Vault/Towny Error

2012-04-29 17:49:17 [INFO] [Vault] Enabling Vault v1.2.15-b172

2012-04-29 17:49:17 [INFO] [Vault][Economy] Essentials Economy found: Waiting

2012-04-29 17:49:17 [INFO] [Vault][Economy] iConomy 6 found: Waiting

2012-04-29 17:49:17 [INFO] [Vault][Permission] GroupManager found: Waiting

2012-04-29 17:49:17 [INFO] [Vault][Permission] SuperPermissions loaded as backup permission system.

2012-04-29 17:49:17 [INFO] [Vault][Chat] GroupManager found: Waiting

2012-04-29 17:49:17 [SEVERE] Error occurred while enabling Vault v1.2.15-b172 (Is it up to date?)

java.lang.NoClassDefFoundError: com/palmergames/bukkit/towny/NotRegisteredException

    at net.milkbowl.vault.Vault.loadChat(Vault.java:214)

    at net.milkbowl.vault.Vault.onEnable(Vault.java:109)

    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:250)

    at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:232)

    at org.bukkit.craftbukkit.CraftServer.<init>(CraftServer.java:184)

    at net.minecraft.server.ServerConfigurationManager.<init>(ServerConfigurationManager.java:53)

    at net.minecraft.server.MinecraftServer.init(MinecraftServer.java:156)

    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:422)

    at net.minecraft.server.ThreadServerApplication.run(SourceFile:492)

Caused by: java.lang.ClassNotFoundException: com.palmergames.bukkit.towny.NotRegisteredException

    at java.net.URLClassLoader$1.run(URLClassLoader.java:366)

    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)

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

    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)

    at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:41)

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

    at java.lang.ClassLoader.loadClass(ClassLoader.java:423)

    at java.lang.ClassLoader.loadClass(ClassLoader.java:356)

    ... 12 more