chairz broken

15:38:10 [INFO] This server is running CraftBukkit version git-Bukkit-1.4.7-R0.1
-1-gf172c52-b2603jnks (MC: 1.4.7) (Implementing API version 1.4.7-R0.2-SNAPSHOT)

15:38:10 [SEVERE] Could not load 'plugins\Chairs.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.NoClassDefFoundError: net/mi
necraft/server/v1_4_6/DataWatcher
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.j
ava:184)
        at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.
java:305)
        at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager
.java:230)
        at org.bukkit.craftbukkit.v1_4_R1.CraftServer.loadPlugins(CraftServer.ja
va:239)
        at org.bukkit.craftbukkit.v1_4_R1.CraftServer.<init>(CraftServer.java:21
7)
        at net.minecraft.server.v1_4_R1.PlayerList.<init>(PlayerList.java:52)
        at net.minecraft.server.v1_4_R1.DedicatedPlayerList.<init>(SourceFile:11
)
        at net.minecraft.server.v1_4_R1.DedicatedServer.init(DedicatedServer.jav
a:104)
        at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java
:399)
        at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:8
49)
Caused by: java.lang.NoClassDefFoundError: net/minecraft/server/v1_4_6/DataWatch
er
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Unknown Source)
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.j
ava:173)
        ... 9 more
Caused by: java.lang.ClassNotFoundException: net.minecraft.server.v1_4_6.DataWat
cher
        at org.bukkit.plugin.java.PluginClassLoader.findClass0(PluginClassLoader
.java:70)
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.
java:53)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        ... 12 more