Denizen debug output

13:45:52 [SEVERE] Error occurred while enabling Denizen v0.8-prerelease (Is it up to date?)
java.lang.NoClassDefFoundError: net/minecraft/server/v1_5_R1/EntityLiving
        at net.aufdemrand.denizen.scripts.ScriptHelper._concatenateCoreScripts(ScriptHelper.java:64)
        at net.aufdemrand.denizen.scripts.ScriptHelper.reloadScripts(ScriptHelper.java:28)
        at net.aufdemrand.denizen.Denizen.onEnable(Denizen.java:183)
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:457)
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:381)
        at org.bukkit.craftbukkit.v1_5_R2.CraftServer.loadPlugin(CraftServer.java:282)
        at org.bukkit.craftbukkit.v1_5_R2.CraftServer.enablePlugins(CraftServer.java:264)
        at net.minecraft.server.v1_5_R2.MinecraftServer.j(MinecraftServer.java:303)
        at net.minecraft.server.v1_5_R2.MinecraftServer.e(MinecraftServer.java:282)
        at net.minecraft.server.v1_5_R2.MinecraftServer.a(MinecraftServer.java:242)
        at net.minecraft.server.v1_5_R2.DedicatedServer.init(DedicatedServer.java:150)
        at net.minecraft.server.v1_5_R2.MinecraftServer.run(MinecraftServer.java:381)
        at net.minecraft.server.v1_5_R2.ThreadServerApplication.run(SourceFile:573)
Caused by: java.lang.ClassNotFoundException: net.minecraft.server.v1_5_R1.EntityLiving
        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(ClassLoader.java:423)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
        ... 14 more