Error beim joinen

org.bukkit.command.CommandException: Unhandled exception executing command 'bm' in plugin BeastMode v0.3
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:180) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        at org.bukkit.craftbukkit.v1_7_R2.CraftServer.dispatchCommand(CraftServer.java:696) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        at net.minecraft.server.v1_7_R2.PlayerConnection.handleCommand(PlayerConnection.java:952) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        at net.minecraft.server.v1_7_R2.PlayerConnection.a(PlayerConnection.java:814) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        at net.minecraft.server.v1_7_R2.PacketPlayInChat.a(PacketPlayInChat.java:28) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        at net.minecraft.server.v1_7_R2.PacketPlayInChat.handle(PacketPlayInChat.java:47) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        at net.minecraft.server.v1_7_R2.NetworkManager.a(NetworkManager.java:147) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        at net.minecraft.server.v1_7_R2.ServerConnection.c(SourceFile:134) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        at net.minecraft.server.v1_7_R2.MinecraftServer.v(MinecraftServer.java:657) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        at net.minecraft.server.v1_7_R2.DedicatedServer.v(DedicatedServer.java:250) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        at net.minecraft.server.v1_7_R2.MinecraftServer.u(MinecraftServer.java:548) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        at net.minecraft.server.v1_7_R2.MinecraftServer.run(MinecraftServer.java:459) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        at net.minecraft.server.v1_7_R2.ThreadServerApplication.run(SourceFile:618) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
Caused by: java.lang.NoClassDefFoundError: org/bukkit/craftbukkit/v1_7_R1/entity/CraftPlayer
        at org.dsdsds123100.Main.PlayerData.<init>(PlayerData.java:27) ~[?:?]
        at org.dsdsds123100.Main.Arena.JoinArena(Arena.java:465) ~[?:?]
        at org.dsdsds123100.Main.Main.onCommand(Main.java:457) ~[?:?]
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        ... 13 more
Caused by: java.lang.ClassNotFoundException: org.bukkit.craftbukkit.v1_7_R1.entity.CraftPlayer
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:67) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:62) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        at java.lang.ClassLoader.loadClass(ClassLoader.java:425) ~[?:1.7.0_55]
        at java.lang.ClassLoader.loadClass(ClassLoader.java:358) ~[?:1.7.0_55]
        at org.dsdsds123100.Main.PlayerData.<init>(PlayerData.java:27) ~[?:?]
        at org.dsdsds123100.Main.Arena.JoinArena(Arena.java:465) ~[?:?]
        at org.dsdsds123100.Main.Main.onCommand(Main.java:457) ~[?:?]
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-14-g8f8716c-b3042jnks]
        ... 13 more