[22:26:02 ERROR]: Could not pass event InventoryClickEvent to Megakilof v1.0
org.bukkit.event.EventException: null
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:309) ~[server2.jar:git-Spigot-f56e2e7-50fbc3f]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[server2.jar:git-Spigot-f56e2e7-50fbc3f]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:500) ~[server2.jar:git-Spigot-f56e2e7-50fbc3f]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:485) ~[server2.jar:git-Spigot-f56e2e7-50fbc3f]
        at net.minecraft.server.v1_13_R2.PlayerConnection.a(PlayerConnection.java:2122) ~[server2.jar:git-Spigot-f56e2e7-50fbc3f]
        at net.minecraft.server.v1_13_R2.PacketPlayInWindowClick.a(SourceFile:33) ~[server2.jar:git-Spigot-f56e2e7-50fbc3f]
        at net.minecraft.server.v1_13_R2.PacketPlayInWindowClick.a(SourceFile:10) ~[server2.jar:git-Spigot-f56e2e7-50fbc3f]
        at net.minecraft.server.v1_13_R2.PlayerConnectionUtils.a(SourceFile:10) ~[server2.jar:git-Spigot-f56e2e7-50fbc3f]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:?]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:?]
        at net.minecraft.server.v1_13_R2.SystemUtils.a(SourceFile:199) [server2.jar:git-Spigot-f56e2e7-50fbc3f]
        at net.minecraft.server.v1_13_R2.MinecraftServer.b(MinecraftServer.java:896) [server2.jar:git-Spigot-f56e2e7-50fbc3f]
        at net.minecraft.server.v1_13_R2.DedicatedServer.b(DedicatedServer.java:417) [server2.jar:git-Spigot-f56e2e7-50fbc3f]
        at net.minecraft.server.v1_13_R2.MinecraftServer.a(MinecraftServer.java:831) [server2.jar:git-Spigot-f56e2e7-50fbc3f]
        at net.minecraft.server.v1_13_R2.MinecraftServer.run(MinecraftServer.java:729) [server2.jar:git-Spigot-f56e2e7-50fbc3f]
        at java.lang.Thread.run(Unknown Source) [?:?]
Caused by: java.lang.NullPointerException
        at pl.daffit.megakilof.MegaKilofPlugin.onInventoryClickEvent(MegaKilofPlugin.java:82) ~[?:?]
        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:305) ~[server2.jar:git-Spigot-f56e2e7-50fbc3f]
        ... 15 more