Error

[11:20:35 ERROR]: Could not pass event InventoryClickEvent to Moderator v2.0.0-pre.1
org.bukkit.event.EventException: null
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:309) ~[spigot-1.13.2.jar:git-Spigot-f56e2e7-ad6070d]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot-1.13.2.jar:git-Spigot-f56e2e7-ad6070d]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:500) ~[spigot-1.13.2.jar:git-Spigot-f56e2e7-ad6070d]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:485) ~[spigot-1.13.2.jar:git-Spigot-f56e2e7-ad6070d]
        at net.minecraft.server.v1_13_R2.PlayerConnection.a(PlayerConnection.java:2123) ~[spigot-1.13.2.jar:git-Spigot-f56e2e7-ad6070d]
        at net.minecraft.server.v1_13_R2.PacketPlayInWindowClick.a(SourceFile:33) ~[spigot-1.13.2.jar:git-Spigot-f56e2e7-ad6070d]
        at net.minecraft.server.v1_13_R2.PacketPlayInWindowClick.a(SourceFile:10) ~[spigot-1.13.2.jar:git-Spigot-f56e2e7-ad6070d]
        at net.minecraft.server.v1_13_R2.PlayerConnectionUtils.a(SourceFile:10) ~[spigot-1.13.2.jar:git-Spigot-f56e2e7-ad6070d]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_191]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_191]
        at net.minecraft.server.v1_13_R2.SystemUtils.a(SourceFile:199) [spigot-1.13.2.jar:git-Spigot-f56e2e7-ad6070d]
        at net.minecraft.server.v1_13_R2.MinecraftServer.b(MinecraftServer.java:896) [spigot-1.13.2.jar:git-Spigot-f56e2e7-ad6070d]
        at net.minecraft.server.v1_13_R2.DedicatedServer.b(DedicatedServer.java:417) [spigot-1.13.2.jar:git-Spigot-f56e2e7-ad6070d]
        at net.minecraft.server.v1_13_R2.MinecraftServer.a(MinecraftServer.java:831) [spigot-1.13.2.jar:git-Spigot-f56e2e7-ad6070d]
        at net.minecraft.server.v1_13_R2.MinecraftServer.run(MinecraftServer.java:729) [spigot-1.13.2.jar:git-Spigot-f56e2e7-ad6070d]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_191]
Caused by: java.lang.NullPointerException
        at net.DeltaWings.Minecraft.Moderator.Commands.Tban.lambda$onCommand$0(Tban.java:67) ~[?:?]
        at net.DeltaWings.Minecraft.Moderator.Custom.Gui.menuClick(Gui.java:175) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_191]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_191]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_191]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_191]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:305) ~[spigot-1.13.2.jar:git-Spigot-f56e2e7-ad6070d]
        ... 15 more