25.12 13:14:14 [Server] WARN [Zombies] Task #13693 for Zombies v0.9.0 generated an exception
25.12 13:14:14 [Server] INFO java.lang.IllegalArgumentException: Material cannot be null
25.12 13:14:14 [Server] INFO at org.apache.commons.lang.Validate.notNull(Validate.java:192) ~[patched_1.13.2.jar:git-Paper-474]
25.12 13:14:14 [Server] INFO at org.bukkit.inventory.ItemStack.<init>(ItemStack.java:73) ~[patched_1.13.2.jar:git-Paper-474]
25.12 13:14:14 [Server] INFO at org.bukkit.inventory.ItemStack.<init>(ItemStack.java:61) ~[patched_1.13.2.jar:git-Paper-474]
25.12 13:14:14 [Server] INFO at Utils.ItemStackUtils.getItem(ItemStackUtils.java:189) ~[?:?]
25.12 13:14:14 [Server] INFO at Handlers.MenuHandler.update(MenuHandler.java:192) ~[?:?]
25.12 13:14:14 [Server] INFO at Handlers.MenuHandler$1.run(MenuHandler.java:50) ~[?:?]
25.12 13:14:14 [Server] INFO at org.bukkit.craftbukkit.v1_13_R2.scheduler.CraftTask.run(CraftTask.java:82) ~[patched_1.13.2.jar:git-Paper-474]
25.12 13:14:14 [Server] INFO at org.bukkit.craftbukkit.v1_13_R2.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:448) ~[patched_1.13.2.jar:git-Paper-474]
25.12 13:14:14 [Server] INFO at net.minecraft.server.v1_13_R2.MinecraftServer.b(MinecraftServer.java:1008) ~[patched_1.13.2.jar:git-Paper-474]
25.12 13:14:14 [Server] INFO at net.minecraft.server.v1_13_R2.DedicatedServer.b(DedicatedServer.java:439) ~[patched_1.13.2.jar:git-Paper-474]
25.12 13:14:14 [Server] INFO at net.minecraft.server.v1_13_R2.MinecraftServer.a(MinecraftServer.java:943) ~[patched_1.13.2.jar:git-Paper-474]
25.12 13:14:14 [Server] INFO at net.minecraft.server.v1_13_R2.MinecraftServer.run(MinecraftServer.java:841) ~[patched_1.13.2.jar:git-Paper-474]
25.12 13:14:14 [Server] INFO at java.lang.Thread.run(Thread.java:748) [?:1.8.0_191]