werewolf Error

[13:07:45 ERROR]: Could not pass event PlayerToggleSneakEvent to Werewolf v0.6.3
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:320) ~[craftbukkit-dev-3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[craftbukkit-dev-3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:486) [craftbukkit-dev-3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:471) [craftbukkit-dev-3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
        at net.minecraft.server.v1_7_R1.PlayerConnection.a(PlayerConnection.java:1009) [craftbukkit-dev-3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
        at net.minecraft.server.v1_7_R1.PacketPlayInEntityAction.a(SourceFile:51) [craftbukkit-dev-3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
        at net.minecraft.server.v1_7_R1.PacketPlayInEntityAction.handle(SourceFile:9) [craftbukkit-dev-3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
        at net.minecraft.server.v1_7_R1.NetworkManager.a(NetworkManager.java:146) [craftbukkit-dev-3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
        at net.minecraft.server.v1_7_R1.ServerConnection.c(SourceFile:134) [craftbukkit-dev-3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
        at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:655) [craftbukkit-dev-3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
        at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:250) [craftbukkit-dev-3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
        at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:545) [craftbukkit-dev-3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
        at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:457) [craftbukkit-dev-3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
        at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [craftbukkit-dev-3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
Caused by: java.lang.NullPointerException
        at net.minecraft.server.v1_7_R1.DataWatcher.watch(SourceFile:135) ~[craftbukkit-dev-3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
        at com.dogonfire.werewolf.WerewolfSkin.setCrouch(WerewolfSkin.java:77) ~[?:?]
        at com.dogonfire.werewolf.listeners.PlayerListener.onPlayerToggleSneak(PlayerListener.java:191) ~[?:?]
        at sun.reflect.GeneratedMethodAccessor641.invoke(Unknown Source) ~[?:?]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.7.0_51]
        at java.lang.reflect.Method.invoke(Method.java:606) ~[?:1.7.0_51]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:318) ~[craftbukkit-dev-3022.jar:git-Bukkit-1.7.2-R0.3-2-g85f5776-b3022jnks]
        ... 13 more