Problème de compatibilité avec NoCheatPlus

Bonjour
Sur mon serveur il y a le plugin Merci de vous Connecter/S'inscrire pour voir les liens. ainsi que le plugin Merci de vous Connecter/S'inscrire pour voir les liens. (un tout petit plugin utile)
J'aimerais pouvoir utiliser ces 2 plugins correctement sur mon serveur, le problème c'est quand un joueur se déconnecte, parfois sur la console ça affiche :

Code:

[Server thread/ERROR]: Could not pass event InventoryCloseEvent to Heads v1.0-SNAPSHOT
org.bukkit.event.EventException
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at org.bukkit.craftbukkit.v1_10_R1.event.CraftEventFactory.handleInventoryCloseEvent(CraftEventFactory.java:873) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at net.minecraft.server.v1_10_R1.EntityPlayer.closeInventory(EntityPlayer.java:839) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at org.bukkit.craftbukkit.v1_10_R1.entity.CraftHumanEntity.closeInventory(CraftHumanEntity.java:375) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at fr.neatmonster.nocheatplus.checks.inventory.Open.check(Open.java:74) [NoCheatPlus.jar:?]
    at fr.neatmonster.nocheatplus.checks.inventory.InventoryListener.playerLeaves(InventoryListener.java:431) [NoCheatPlus.jar:?]
    at fr.neatmonster.nocheatplus.NoCheatPlus.onLeave(NoCheatPlus.java:1367) [NoCheatPlus.jar:?]
    at fr.neatmonster.nocheatplus.NoCheatPlus$7.onPlayerQuit(NoCheatPlus.java:1324) [NoCheatPlus.jar:?]
    at sun.reflect.GeneratedMethodAccessor750.invoke(Unknown Source) ~[?:?]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_72]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_72]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at net.minecraft.server.v1_10_R1.PlayerList.disconnect(PlayerList.java:385) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at net.minecraft.server.v1_10_R1.PlayerConnection.a(PlayerConnection.java:1061) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at net.minecraft.server.v1_10_R1.NetworkManager.handleDisconnection(NetworkManager.java:316) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at net.minecraft.server.v1_10_R1.ServerConnection.c(ServerConnection.java:174) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at net.minecraft.server.v1_10_R1.MinecraftServer.D(MinecraftServer.java:827) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at net.minecraft.server.v1_10_R1.DedicatedServer.D(DedicatedServer.java:400) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at net.minecraft.server.v1_10_R1.MinecraftServer.C(MinecraftServer.java:668) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at net.minecraft.server.v1_10_R1.MinecraftServer.run(MinecraftServer.java:567) [spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    at java.lang.Thread.run(Thread.java:745) [?:1.8.0_72]
Caused by: java.lang.NullPointerException
    at co.insou.gui.GUIManager$GUIListener.on(GUIManager.java:75) ~[?:?]
    at sun.reflect.GeneratedMethodAccessor259.invoke(Unknown Source) ~[?:?]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_72]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_72]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302) ~[spigot-1.10.2.jar:git-Spigot-f9671b8-48b88ed]
    ... 26 more

Et j'aimerais que ça arrête de faire ça car ça spam la console et pour chercher une ligne c'est compliqué

Merci pour votre aide