Как исправить ошибку в плагине MythicMobs : an internal error occurred while attempting to perform this command

только скачал плагин MythicMobs на сервер и выдает ошибку сервер стоит на версии 1.21.1 вот лог из консоли
[10:42:09] [Server thread/INFO]: M_Gorshenev1973 issued server command: /mythicmobs
[10:42:09] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'mythicmobs' in plugin MythicMobs v5.8.1-${CI_COMMIT_SHORT_SHA}
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:47) ~[spigot-api-1.21.1-R0.1-SNAPSHOT.jar:?]
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:150) ~[spigot-api-1.21.1-R0.1-SNAPSHOT.jar:?]
at org.bukkit.craftbukkit.v1_21_R1.CraftServer.dispatchCommand(CraftServer.java:922) ~[spigot-1.21.1-R0.1-SNAPSHOT.jar:4344-Spigot-a759b62-19bf846]
at org.bukkit.craftbukkit.v1_21_ R1.command.BukkitCommandWrapper.run (BukkitCommandWrapper.java:50) ~[spigot-1.21.1-R0.1-SNAPSHOT.jar:4344-Spigot-a759b62-19bf846]
at com.mojang.brigadier.context.ContextChain.runExecutable(ContextChain.java:73) ~[brigadier-1.2.9.jar:?]
at net.minecraft.commands.execution.tasks.ExecuteCommand.a(SourceFile:29) ~[spigot-1.21.1-R0.1-SNAPSHOT.jar:4344-Spigot-a759b62-19bf846]
at net.minecraft.commands.execution.tasks.ExecuteCommand.execute(SourceFile:13) ~[spigot-1.21.1-R0.1-SNAPSHOT.jar:4344-Spigot-a759b62-19bf846]
at net.minecraft.commands.execution.UnboundEntryAction.a(SourceFile:8) ~[spigot-1.21.1-R0.1-SNAPSHOT.jar:4344-Spigot-a759b62-19bf846]
at net.minecraft.commands.execution.CommandQueueEntry.a(SourceFile:8) ~[spigot-1.21.1-R0.1-SNAPSHOT.jar:4344-Spigot-a759b62-19bf846]
at net.minecraft.commands.execution.ExecutionContext.a(SourceFile:107) ~[spigot-1.21.1-R0.1-SNAPSHOT.jar:4344-Spigot-a759b62-19bf846]
at net.minecraft.commands.CommandDispatcher.a(CommandDispatcher.java:414) ~[spigot-1.21.1-R0.1-SNAPSHOT.jar:4344-Spigot-a759b62-19bf846]
at net.minecraft.commands.CommandDispatcher.performCommand(CommandDispatcher.java:336) ~[spigot-1.21.1-R0.1-SNAPSHOT.jar:4344-Spigot-a759b62-19bf846]
at net.minecraft.commands.CommandDispatcher.a(CommandDispatcher.java:323) ~[spigot-1.21.1-R0.1-SNAPSHOT.jar:4344-Spigot-a759b62-19bf846]
at net.minecraft.server.network .PlayerConnection.b(PlayerConnection.java:1842) ~[spigot-1.21.1-R0.1-SNAPSHOT.jar:4344-Spigot-a759b62-19bf846]
at net.minecraft.server.network .PlayerConnection.lambda$handleChatCommand$7(PlayerConnection.java:1818) ~[spigot-1.21.1-R0.1-SNAPSHOT.jar:4344-Spigot-a759b62-19bf846]
at net.minecraft.server.TickTask.run (SourceFile:18) ~[spigot-1.21.1-R0.1-SNAPSHOT.jar:4344-Spigot-a759b62-19bf846]
at net.minecraft.util.thread.IAsyncTaskHandler.d(SourceFile:162) ~[spigot-1.21.1-R0.1-SNAPSHOT.jar:4344-Spigot-a759b62-19bf846]
at net.minecraft.util.thread.IAsyncTaskHandlerReentrant.d(SourceFile:23) ~[spigot-1.21.1-R0.1-SNAPSHOT.jar:4344-Spigot-a759b62-19bf846]
at net.minecraft.server.MinecraftServer.b(MinecraftServer.java:1270) ~[spigot-1.21.1-R0.1