Herochat Thunder

3:05:48 [SEVERE] Could not pass event PlayerChatEvent to Herochat
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:332)
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:477)
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:462)
        at net.minecraft.server.MinecraftServer.q(MinecraftServer.java:517)
        at net.minecraft.server.DedicatedServer.q(DedicatedServer.java:212)
        at net.minecraft.server.MinecraftServer.p(MinecraftServer.java:476)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:408)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:539)
Caused by: java.lang.RuntimeException: Chatter (thunder13959) not found.
        at com.dthielke.herochat.MessageHandler.handle(MessageHandler.java:81)
        at com.dthielke.herochat.HCPlayerListener.onPlayerChat(HCPlayerListener.java:19)
        at sun.reflect.GeneratedMethodAccessor45.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:330)
        ... 8 more