Denizen Plugin Problem

9:38:42 PM [SEVERE] Could not load 'plugins\denizen-0.76-SNAPSHOT.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.NoClassDefFoundError: net/citizensnpcs/command/exception/RequirementMissingException
at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:182)
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.java:239)
at org.bukkit.craftbukkit.v1_4_R1.CraftServer.<init>(CraftServer.java:217)
at net.minecraft.server.v1_4_R1.PlayerList.<init>(PlayerList.java:55)
at net.minecraft.server.v1_4_R1.DedicatedPlayerList.<init>(SourceFile:11)
at net.minecraft.server.v1_4_R1.DedicatedServer.init(DedicatedServer.java:104)
at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java:399)
at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:849)
Caused by: java.lang.NoClassDefFoundError: net/citizensnpcs/command/exception/RequirementMissingException
at net.aufdemrand.denizen.scripts.ScriptEngine.<init>(ScriptEngine.java:35)
at net.aufdemrand.denizen.Denizen.<init>(Denizen.java:57)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:178)
... 9 more
Caused by: java.lang.ClassNotFoundException: net.citizensnpcs.command.exception.RequirementMissingException
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at org.bukkit.plugin.java.PluginClassLoader.findClass0(PluginClassLoader.java:80)
at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:53)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 16 more