[15:20:36 ERROR]: Could not pass event InventoryClickEvent to ChangeSpawners v1.0
org.bukkit.event.EventException: null
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:308) ~[spigot-latest.jar:git-Spigot-69774b3-80c43fc]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot-latest.jar:git-Spigot-69774b3-80c43fc]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:500) ~[spigot-latest.jar:git-Spigot-69774b3-80c43fc]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:485) ~[spigot-latest.jar:git-Spigot-69774b3-80c43fc]
        at net.minecraft.server.v1_13_R1.PlayerConnection.a(PlayerConnection.java:2130) ~[spigot-latest.jar:git-Spigot-69774b3-80c43fc]
        at net.minecraft.server.v1_13_R1.PacketPlayInWindowClick.a(SourceFile:33) ~[spigot-latest.jar:git-Spigot-69774b3-80c43fc]
        at net.minecraft.server.v1_13_R1.PacketPlayInWindowClick.a(SourceFile:10) ~[spigot-latest.jar:git-Spigot-69774b3-80c43fc]
        at net.minecraft.server.v1_13_R1.PlayerConnectionUtils.a(SourceFile:10) ~[spigot-latest.jar:git-Spigot-69774b3-80c43fc]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:?]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:?]
        at net.minecraft.server.v1_13_R1.SystemUtils.a(SourceFile:198) [spigot-latest.jar:git-Spigot-69774b3-80c43fc]
        at net.minecraft.server.v1_13_R1.MinecraftServer.w(MinecraftServer.java:884) [spigot-latest.jar:git-Spigot-69774b3-80c43fc]
        at net.minecraft.server.v1_13_R1.DedicatedServer.w(DedicatedServer.java:411) [spigot-latest.jar:git-Spigot-69774b3-80c43fc]
        at net.minecraft.server.v1_13_R1.MinecraftServer.v(MinecraftServer.java:819) [spigot-latest.jar:git-Spigot-69774b3-80c43fc]
        at net.minecraft.server.v1_13_R1.MinecraftServer.run(MinecraftServer.java:717) [spigot-latest.jar:git-Spigot-69774b3-80c43fc]
        at java.lang.Thread.run(Unknown Source) [?:?]
Caused by: java.lang.IllegalStateException: e.currentItem must not be null
        at me.reedzev.spawners.SpawnerMenu.onInventoryClick(SpawnerMenu.kt:76) ~[?:?]
        at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
        at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:?]
        at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:?]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:?]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:304) ~[spigot-latest.jar:git-Spigot-69774b3-80c43fc]
        ... 15 more