> [14:55:58 ERROR]: Could not pass event InventoryCloseEvent to Factions v2.13.7
org.bukkit.event.EventException
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:302) ~[server.jar:git-TacoSpigot-aa1afff]
at co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:78) ~[server.jar:git-TacoSpigot-aa1afff]
at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[server.jar:git-TacoSpigot-aa1afff]
at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:501) [server.jar:git-TacoSpigot-aa1afff]
at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:486) [server.jar:git-TacoSpigot-aa1afff]
at org.bukkit.craftbukkit.v1_8_R3.event.CraftEventFactory.handleInventoryCloseEvent(CraftEventFactory.java:885) [server.jar:git-TacoSpigot-aa1afff]
at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:1525) [?:git-TacoSpigot-aa1afff]
at net.minecraft.server.v1_8_R3.PacketPlayInCloseWindow.a(PacketPlayInCloseWindow.java:18) [server.jar:git-TacoSpigot-aa1afff]
at net.minecraft.server.v1_8_R3.PacketPlayInCloseWindow.a(PacketPlayInCloseWindow.java:1) [server.jar:git-TacoSpigot-aa1afff]
at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [server.jar:git-TacoSpigot-aa1afff]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_212]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_212]
at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [server.jar:git-TacoSpigot-aa1afff]
at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:773) [server.jar:git-TacoSpigot-aa1afff]
at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:386) [server.jar:git-TacoSpigot-aa1afff]
at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:712) [server.jar:git-TacoSpigot-aa1afff]
at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:615) [server.jar:git-TacoSpigot-aa1afff]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_212]
Caused by: java.lang.IllegalStateException: Unable to save item stacks.
at com.massivecraft.factions.util.InventoryUtil.toBase64(InventoryUtil.java:102) ~[?:?]
at com.massivecraft.factions.entity.Faction.saveInventory(Faction.java:569) ~[?:?]
at gg.halcyon.upgrades.upgrades.FactionChestUpgrade.onInventoryClose(FactionChestUpgrade.java:200) ~[?:?]
at sun.reflect.GeneratedMethodAccessor516.invoke(Unknown Source) ~[?:?]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_212]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_212]
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:300) ~[server.jar:git-TacoSpigot-aa1afff]
... 17 more
Caused by: java.lang.NullPointerException: null key in entry: null=0
at com.google.common.collect.CollectPreconditions.checkEntryNotNull(CollectPreconditions.java:31) ~[server.jar:git-TacoSpigot-aa1afff]
at com.google.common.collect.ImmutableMap.entryOf(ImmutableMap.java:135) ~[server.jar:git-TacoSpigot-aa1afff]
at com.google.common.collect.ImmutableMap$Builder.put(ImmutableMap.java:206) ~[server.jar:git-TacoSpigot-aa1afff]
at org.bukkit.craftbukkit.v1_8_R3.inventory.CraftMetaItem.serializeEnchantments(CraftMetaItem.java:915) ~[server.jar:git-TacoSpigot-aa1afff]
at org.bukkit.craftbukkit.v1_8_R3.inventory.CraftMetaItem.serialize(CraftMetaItem.java:864) ~[server.jar:git-TacoSpigot-aa1afff]
at org.bukkit.craftbukkit.v1_8_R3.inventory.CraftMetaItem.serialize(CraftMetaItem.java:850) ~[server.jar:git-TacoSpigot-aa1afff]
at org.bukkit.util.io.Wrapper.newWrapper(Wrapper.java:17) ~[server.jar:git-TacoSpigot-aa1afff]
at org.bukkit.util.io.BukkitObjectOutputStream.replaceObject(BukkitObjectOutputStream.java:47) ~[server.jar:git-TacoSpigot-aa1afff]
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1144) ~[?:1.8.0_212]
at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378) ~[?:1.8.0_212]
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174) ~[?:1.8.0_212]
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548) ~[?:1.8.0_212]
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509) ~[?:1.8.0_212]
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432) ~[?:1.8.0_212]
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178) ~[?:1.8.0_212]
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548) ~[?:1.8.0_212]
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509) ~[?:1.8.0_212]
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432) ~[?:1.8.0_212]
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178) ~[?:1.8.0_212]
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348) ~[?:1.8.0_212]
at com.massivecraft.factions.util.InventoryUtil.toBase64(InventoryUtil.java:95) ~[?:?]
at com.massivecraft.factions.entity.Faction.saveInventory(Faction.java:569) ~[?:?]
at gg.halcyon.upgrades.upgrades.FactionChestUpgrade.onInventoryClose(FactionChestUpgrade.java:200) ~[?:?]
at sun.reflect.GeneratedMethodAccessor516.invoke(Unknown Source) ~[?:?]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_212]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_212]
at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:300) ~[server.jar:git-TacoSpigot-aa1afff]
... 17 more