2013-07-11 15:52:06 [SEVERE] Could not pass event EntityDamageByEntityEvent to PvPToggle v3.0.0
org.bukkit.event.EventException
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:427)
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
	at org.bukkit.plugin.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:30)
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:478)
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:463)
	at org.bukkit.craftbukkit.v1_6_R2.event.CraftEventFactory.callEvent(CraftEventFactory.java:96)
	at org.bukkit.craftbukkit.v1_6_R2.event.CraftEventFactory.callEntityDamageEvent(CraftEventFactory.java:400)
	at org.bukkit.craftbukkit.v1_6_R2.event.CraftEventFactory.handleEntityDamageEvent(CraftEventFactory.java:425)
	at net.minecraft.server.v1_6_R2.EntityLiving.damageEntity(EntityLiving.java:621)
	at net.minecraft.server.v1_6_R2.EntityHuman.damageEntity(EntityHuman.java:705)
	at net.minecraft.server.v1_6_R2.EntityPlayer.damageEntity(EntityPlayer.java:371)
	at net.minecraft.server.v1_6_R2.EntityMonster.m(EntityMonster.java:79)
	at net.minecraft.server.v1_6_R2.EntityMonster.a(EntityMonster.java:105)
	at net.minecraft.server.v1_6_R2.EntitySpider.a(EntitySpider.java:87)
	at net.minecraft.server.v1_6_R2.EntityCreature.bk(EntityCreature.java:66)
	at net.minecraft.server.v1_6_R2.EntityLiving.c(EntityLiving.java:1402)
	at net.minecraft.server.v1_6_R2.EntityInsentient.c(EntityInsentient.java:303)
	at net.minecraft.server.v1_6_R2.EntityMonster.c(EntityMonster.java:20)
	at net.minecraft.server.v1_6_R2.EntityLiving.l_(EntityLiving.java:1261)
	at net.minecraft.server.v1_6_R2.EntityInsentient.l_(EntityInsentient.java:147)
	at net.minecraft.server.v1_6_R2.EntityMonster.l_(EntityMonster.java:24)
	at net.minecraft.server.v1_6_R2.EntitySpider.l_(EntitySpider.java:18)
	at net.minecraft.server.v1_6_R2.World.entityJoinedWorld(World.java:1457)
	at net.minecraft.server.v1_6_R2.World.playerJoinedWorld(World.java:1432)
	at net.minecraft.server.v1_6_R2.World.tickEntities(World.java:1304)
	at net.minecraft.server.v1_6_R2.WorldServer.tickEntities(WorldServer.java:517)
	at net.minecraft.server.v1_6_R2.MinecraftServer.t(MinecraftServer.java:571)
	at net.minecraft.server.v1_6_R2.DedicatedServer.t(DedicatedServer.java:239)
	at net.minecraft.server.v1_6_R2.MinecraftServer.s(MinecraftServer.java:481)
	at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:413)
	at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)
Caused by: java.lang.NoClassDefFoundError: net/citizensnpcs/api/CitizensAPI
	at com.sleelin.pvptoggle.listeners.EntityListener.onEntityDamage(EntityListener.java:51)
	at sun.reflect.GeneratedMethodAccessor179.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:601)
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425)
	... 30 more