[10:48:37 ERROR]: Error occurred while enabling KitPvP v2.1.6 (Is it up to date?)
java.lang.IllegalArgumentException: Cannot match a material with null or empty material name
        at org.apache.commons.lang.Validate.notEmpty(Validate.java:321) ~[patched_1.16.4.jar:git-Paper-338]
        at com.planetgallium.kitpvp.XMaterial.matchXMaterial(XMaterial.java:1495) ~[?:?]
        at com.planetgallium.kitpvp.menu.KitMenu.create(KitMenu.java:32) ~[?:?]
        at com.planetgallium.kitpvp.menu.KitMenu.<init>(KitMenu.java:18) ~[?:?]
        at com.planetgallium.kitpvp.game.Menus.<init>(Menus.java:15) ~[?:?]
        at com.planetgallium.kitpvp.game.Arena.<init>(Arena.java:54) ~[?:?]
        at com.planetgallium.kitpvp.Game.onEnable(Game.java:44) ~[?:?]
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:263) ~[patched_1.16.4.jar:git-Paper-338]
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:380) ~[patched_1.16.4.jar:git-Paper-338]
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:483) ~[patched_1.16.4.jar:git-Paper-338]
        at org.bukkit.craftbukkit.v1_16_R3.CraftServer.enablePlugin(CraftServer.java:501) ~[patched_1.16.4.jar:git-Paper-338]
        at org.bukkit.craftbukkit.v1_16_R3.CraftServer.enablePlugins(CraftServer.java:415) ~[patched_1.16.4.jar:git-Paper-338]
        at net.minecraft.server.v1_16_R3.MinecraftServer.loadWorld(MinecraftServer.java:469) ~[patched_1.16.4.jar:git-Paper-338]
        at net.minecraft.server.v1_16_R3.DedicatedServer.init(DedicatedServer.java:239) ~[patched_1.16.4.jar:git-Paper-338]
        at net.minecraft.server.v1_16_R3.MinecraftServer.w(MinecraftServer.java:936) ~[patched_1.16.4.jar:git-Paper-338]        at net.minecraft.server.v1_16_R3.MinecraftServer.lambda$a$0(MinecraftServer.java:178) ~[patched_1.16.4.jar:git-Paper-338]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_261]