Elite Armor plugin error message

Hey, i wanted to create my own custom armor with elite armor plugin but when i try to get it in the /ea list menu it just doesn't work (other premade sets are working), and then i see that in the server prompt there is this error message once time i click on it :

Code:

[09:20:54] [Server thread/ERROR]: Could not pass event InventoryClickEvent to EliteArmor v6.5.2
org.bukkit.event.EventException: null
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310) ~[spigot-api-1.18.1-R0.1-SNAPSHOT.jar:?]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) ~[spigot-api-1.18.1-R0.1-SNAPSHOT.jar:?]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:589) ~[spigot-api-1.18.1-R0.1-SNAPSHOT.jar:?]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:576) ~[spigot-api-1.18.1-R0.1-SNAPSHOT.jar:?]
    at net.minecraft.server.network.PlayerConnection.a(PlayerConnection.java:2438) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3360-Spigot-f65de01-c2e0bbd]
    at net.minecraft.network.protocol.game.PacketPlayInWindowClick.a(SourceFile:58) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3360-Spigot-f65de01-c2e0bbd]
    at net.minecraft.network.protocol.game.PacketPlayInWindowClick.a(SourceFile:13) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3360-Spigot-f65de01-c2e0bbd]
    at net.minecraft.network.protocol.PlayerConnectionUtils.lambda$0(PlayerConnectionUtils.java:30) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3360-Spigot-f65de01-c2e0bbd]
    at net.minecraft.server.TickTask.run(SourceFile:18) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3360-Spigot-f65de01-c2e0bbd]
    at net.minecraft.util.thread.IAsyncTaskHandler.c(SourceFile:151) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3360-Spigot-f65de01-c2e0bbd]
    at net.minecraft.util.thread.IAsyncTaskHandlerReentrant.c(SourceFile:23) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3360-Spigot-f65de01-c2e0bbd]
    at net.minecraft.server.MinecraftServer.b(MinecraftServer.java:1158) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3360-Spigot-f65de01-c2e0bbd]
    at net.minecraft.server.MinecraftServer.c(MinecraftServer.java:1) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3360-Spigot-f65de01-c2e0bbd]
    at net.minecraft.util.thread.IAsyncTaskHandler.y(SourceFile:125) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3360-Spigot-f65de01-c2e0bbd]
    at net.minecraft.server.MinecraftServer.bf(MinecraftServer.java:1137) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3360-Spigot-f65de01-c2e0bbd]
    at net.minecraft.server.MinecraftServer.y(MinecraftServer.java:1130) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3360-Spigot-f65de01-c2e0bbd]
    at net.minecraft.util.thread.IAsyncTaskHandler.c(SourceFile:134) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3360-Spigot-f65de01-c2e0bbd]
    at net.minecraft.server.MinecraftServer.x(MinecraftServer.java:1114) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3360-Spigot-f65de01-c2e0bbd]
    at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:1038) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3360-Spigot-f65de01-c2e0bbd]
    at net.minecraft.server.MinecraftServer.lambda$0(MinecraftServer.java:304) ~[spigot-1.18.1-R0.1-SNAPSHOT.jar:3360-Spigot-f65de01-c2e0bbd]
    at java.lang.Thread.run(Thread.java:833) [?:?]
Caused by: java.lang.NullPointerException: Cannot invoke "String.contains(java.lang.CharSequence)" because "<local5>" is null
    at net.splodgebox.elitearmor.armor.Armor.createArmor(Armor.java:42) ~[?:?]
    at net.splodgebox.elitearmor.armor.gui.ArmorListGUI.openArmorInventory(ArmorListGUI.java:79) ~[?:?]
    at net.splodgebox.elitearmor.armor.gui.ArmorListGUI.lambda$openListInventory$0(ArmorListGUI.java:62) ~[?:?]
    at net.splodgebox.elitearmor.pluginapi.gui.menu.listeners.BukkitMenuListener.onInventoryClick(BukkitMenuListener.java:31) ~[?:?]
    at jdk.internal.reflect.GeneratedMethodAccessor549.invoke(Unknown Source) ~[?:?]
    at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
    at java.lang.reflect.Method.invoke(Method.java:568) ~[?:?]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot-api-1.18.1-R0.1-SNAPSHOT.jar:?]
    ... 20 more

i tried to restart my server and else... but not working (my server is 1.18 version)