[ERROR] Error occurred while enabling LostSkyWars v2.3.15 (Is it up to date?)

java.lang.NullPointerException

at org.bukkit.inventory.ItemStack.<init>(ItemStack.java:68) ~[PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"4c7641d"]

at org.bukkit.inventory.ItemStack.<init>(ItemStack.java:46) ~[PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"4c7641d"]

at tk.kanaostore.losteddev.skywars.iIIIIIIiiIIIiII.deserializeItemStack(BukkitUtils.java:63) ~[?:?]

at tk.kanaostore.losteddev.skywars.iIiiiiIIIiIIiII.new(NormalSkyWarsKit.java:48) ~[?:?]

at tk.kanaostore.losteddev.skywars.IiiIIIiIIiIIiII.do(Cosmetic.java:92) ~[?:?]

at tk.kanaostore.losteddev.skywars.Main.onEnable(Main.java:72) ~[?:?]

at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:321) ~[PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"4c7641d"]

at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:332) [PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"4c7641d"]

at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:407) [PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"4c7641d"]

at org.bukkit.craftbukkit.v1_8_R3.CraftServer.loadPlugin(CraftServer.java:359) [PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"4c7641d"]

at org.bukkit.craftbukkit.v1_8_R3.CraftServer.enablePlugins(CraftServer.java:318) [PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"4c7641d"]

at net.minecraft.server.v1_8_R3.MinecraftServer.s(MinecraftServer.java:408) [PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"4c7641d"]

at net.minecraft.server.v1_8_R3.MinecraftServer.k(MinecraftServer.java:372) [PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"4c7641d"]

at net.minecraft.server.v1_8_R3.MinecraftServer.a(MinecraftServer.java:327) [PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"4c7641d"]

at net.minecraft.server.v1_8_R3.DedicatedServer.init(DedicatedServer.java:267) [PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"4c7641d"]

at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:563) [PaperSpigot-1.8.8-R0.1-SNAPSHOT-latest.jar:git-PaperSpigot-"4c7641d"]

at java.lang.Thread.run(Thread.java:813) [?:1.8.0_212]