10:41:05 [SEVERE] Could not pass event EntityDamageEvent to Assassination v1.5.0

org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja
va:427)
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.jav
a:62)
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.j
ava:477)
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.j
ava:462)
        at org.bukkit.craftbukkit.v1_5_R3.event.CraftEventFactory.callEvent(Craf
tEventFactory.java:93)
        at org.bukkit.craftbukkit.v1_5_R3.event.CraftEventFactory.callEntityDama
geEvent(CraftEventFactory.java:381)
        at net.minecraft.server.v1_5_R3.EntityLiving.a(EntityLiving.java:959)
        at net.minecraft.server.v1_5_R3.EntityHuman.a(EntityHuman.java:1295)
        at net.minecraft.server.v1_5_R3.Entity.a(Entity.java:772)
        at net.minecraft.server.v1_5_R3.EntityLiving.a(EntityLiving.java:243)
        at net.minecraft.server.v1_5_R3.EntityPlayer.b(EntityPlayer.java:463)
        at net.minecraft.server.v1_5_R3.PlayerConnection.a(PlayerConnection.java
:430)
        at net.minecraft.server.v1_5_R3.Packet10Flying.handle(SourceFile:136)
        at net.minecraft.server.v1_5_R3.NetworkManager.b(NetworkManager.java:292
)
        at net.minecraft.server.v1_5_R3.PlayerConnection.d(PlayerConnection.java
:115)
        at org.getspout.spout.SpoutPlayerConnection.d(SpoutPlayerConnection.java
:195)
        at net.minecraft.server.v1_5_R3.ServerConnection.b(SourceFile:35)
        at net.minecraft.server.v1_5_R3.DedicatedServerConnection.b(SourceFile:3
0)
        at net.minecraft.server.v1_5_R3.MinecraftServer.r(MinecraftServer.java:5
81)
        at net.minecraft.server.v1_5_R3.DedicatedServer.r(DedicatedServer.java:2
26)
        at net.minecraft.server.v1_5_R3.MinecraftServer.q(MinecraftServer.java:4
77)
        at net.minecraft.server.v1_5_R3.MinecraftServer.run(MinecraftServer.java
:410)
        at net.minecraft.server.v1_5_R3.ThreadServerApplication.run(SourceFile:5
73)
Caused by: java.lang.NoSuchMethodError: org.bukkit.event.entity.EntityDamageEven
t.getDamage()D
        at pl.ZamorekPL.Assassination.AListener.onEntityDamage(AListener.java:10
2)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja
va:425)
        ... 22 more