Skellett - could not pass event InventoryClickEvent

[BlazingFiree]

I was wondering Why do I keep getting this error?
because I want to mess up with some inventory events and every time I click on something this exception pops up

[02:32:59 ERROR]: Could not pass event InventoryClickEvent to Skellett v1.9.4a
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302) ~[CraftBukkit.jar:git-Bukkit-18fbb24]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[CraftBukkit.jar:git-Bukkit-18fbb24]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:501) [CraftBukkit.jar:git-Bukkit-18fbb24]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:486) [CraftBukkit.jar:git-Bukkit-18fbb24]
        at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:1564) [CraftBukkit.jar:git-Bukkit-18fbb24]
        at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:31) [CraftBukkit.jar:git-Bukkit-18fbb24]
        at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:9) [CraftBukkit.jar:git-Bukkit-18fbb24]
        at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [CraftBukkit.jar:git-Bukkit-18fbb24]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_121]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_121]
        at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [CraftBukkit.jar:git-Bukkit-18fbb24]
        at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:673) [CraftBukkit.jar:git-Bukkit-18fbb24]
        at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:335) [CraftBukkit.jar:git-Bukkit-18fbb24]
        at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:629) [CraftBukkit.jar:git-Bukkit-18fbb24]
        at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:537) [CraftBukkit.jar:git-Bukkit-18fbb24]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_121]
Caused by: java.lang.NoSuchMethodError: org.bukkit.event.inventory.InventoryClickEvent.getClickedInventory()Lorg/bukkit/inventory/Inventory;
        at com.gmail.thelimeglass.Command.onInventoryClick(Command.java:54) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_121]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_121]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_121]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_121]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:300) ~[CraftBukkit.jar:git-Bukkit-18fbb24]
        ... 15 more

I have no clue how to fix it.... Any suggestions please...?