Error message.

[02:28:18 ERROR]: Could not pass event AsyncPlayerChatEvent to MutinyIRC v1.0.1-r2
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:427) ~[spigot-1.7.26.jar:git-Spigot-1171]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot-1.7.26.jar:git-Spigot-1171]
        at org.bukkit.plugin.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:35) ~[spigot-1.7.26.jar:git-Spigot-1171]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:478) [spigot-1.7.26.jar:git-Spigot-1171]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:460) [spigot-1.7.26.jar:git-Spigot-1171]
        at net.minecraft.server.v1_7_R1.PlayerConnection.chat(PlayerConnection.java:859) [spigot-1.7.26.jar:git-Spigot-1171]
        at net.minecraft.server.v1_7_R1.PlayerConnection.a(PlayerConnection.java:828) [spigot-1.7.26.jar:git-Spigot-1171]
        at net.minecraft.server.v1_7_R1.PacketPlayInChat.a(PacketPlayInChat.java:28) [spigot-1.7.26.jar:git-Spigot-1171]
        at net.minecraft.server.v1_7_R1.PacketPlayInChat$1.run(PacketPlayInChat.java:59) [spigot-1.7.26.jar:git-Spigot-1171]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) [?:1.7.0_21]
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334) [?:1.7.0_21]
        at java.util.concurrent.FutureTask.run(FutureTask.java:166) [?:1.7.0_21]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [?:1.7.0_21]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [?:1.7.0_21]
        at java.lang.Thread.run(Thread.java:722) [?:1.7.0_21]
Caused by: java.lang.ClassCastException: Cannot cast java.lang.Class to net.milkbowl.vault.chat.plugins.Chat_zPermissions
        at java.lang.Class.cast(Class.java:3014) ~[?:1.7.0_21]
        at com.mutinycraft.irc.IRC.formatGameMessage(IRC.java:417) ~[?:?]
        at com.mutinycraft.irc.impl.DefaultChatHandler.onGameMessage(DefaultChatHandler.java:75) ~[?:?]
        at sun.reflect.GeneratedMethodAccessor120.invoke(Unknown Source) ~[?:?]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.7.0_21]
        at java.lang.reflect.Method.invoke(Method.java:601) ~[?:1.7.0_21]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425) ~[spigot-1.7.26.jar:git-Spigot-1171]