[00:52:42 ERROR]: Could not pass event InventoryClickEvent to AdvancedCustomMenu v4.1.2
org.bukkit.event.EventException: null
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot.jar:git-Spigot-2cf50f0-2b93d83]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot.jar:git-Spigot-2cf50f0-2b93d83]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:500) [spigot.jar:git-Spigot-2cf50f0-2b93d83]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:485) [spigot.jar:git-Spigot-2cf50f0-2b93d83]
        at net.minecraft.server.v1_12_R1.PlayerConnection.a(PlayerConnection.java:1889) [spigot.jar:git-Spigot-2cf50f0-2b93d83]
        at net.minecraft.server.v1_12_R1.PacketPlayInWindowClick.a(SourceFile:33) [spigot.jar:git-Spigot-2cf50f0-2b93d83]
        at net.minecraft.server.v1_12_R1.PacketPlayInWindowClick.a(SourceFile:10) [spigot.jar:git-Spigot-2cf50f0-2b93d83]
        at net.minecraft.server.v1_12_R1.PlayerConnectionUtils$1.run(SourceFile:13) [spigot.jar:git-Spigot-2cf50f0-2b93d83]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_191]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_191]
        at net.minecraft.server.v1_12_R1.SystemUtils.a(SourceFile:46) [spigot.jar:git-Spigot-2cf50f0-2b93d83]
        at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:748) [spigot.jar:git-Spigot-2cf50f0-2b93d83]
        at net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:406) [spigot.jar:git-Spigot-2cf50f0-2b93d83]
        at net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:679) [spigot.jar:git-Spigot-2cf50f0-2b93d83]
        at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:577) [spigot.jar:git-Spigot-2cf50f0-2b93d83]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_191]
Caused by: java.util.ConcurrentModificationException
        at java.util.Hashtable$Enumerator.next(Unknown Source) ~[?:1.8.0_191]
        at me.SuperRonanCraft.AdvancedCustomMenu.menus.handlers.list.activities.Delays.load(Delays.java:34) ~[?:?]
        at me.SuperRonanCraft.AdvancedCustomMenu.menus.handlers.list.activities.Delays.<init>(Delays.java:23) ~[?:?]
        at me.SuperRonanCraft.AdvancedCustomMenu.menus.inv.MenuHandler.getDelays(MenuHandler.java:89) ~[?:?]
        at me.SuperRonanCraft.AdvancedCustomMenu.menus.handlers.list.click.ClickHandler.delay(ClickHandler.java:349) ~[?:?]
        at me.SuperRonanCraft.AdvancedCustomMenu.menus.handlers.list.click.ClickHandler.beforeCmd(ClickHandler.java:86) ~[?:?]
        at me.SuperRonanCraft.AdvancedCustomMenu.menus.handlers.list.click.ClickHandler.check(ClickHandler.java:61) ~[?:?]
        at me.SuperRonanCraft.AdvancedCustomMenu.menus.handlers.list.click.ClickHandler.execute(ClickHandler.java:57) ~[?:?]
        at me.SuperRonanCraft.AdvancedCustomMenu.menus.handlers.Handler.click(Handler.java:32) ~[?:?]
        at me.SuperRonanCraft.AdvancedCustomMenu.events.Click.handler(Click.java:24) ~[?:?]
        at me.SuperRonanCraft.AdvancedCustomMenu.events.Click.click(Click.java:16) ~[?:?]
        at me.SuperRonanCraft.AdvancedCustomMenu.events.Listener.clickEvent(Listener.java:47) ~[?:?]
        at sun.reflect.GeneratedMethodAccessor232.invoke(Unknown Source) ~[?:?]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_191]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_191]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302) ~[spigot.jar:git-Spigot-2cf50f0-2b93d83]
        ... 15 more