mm m listactive error

[15:02:39 ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'mm' in plugin MythicMobs v5.4.0-SNAPSHOT-28c6b0f1
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:47) ~[paper-api-1.20.1-R0.1-SNAPSHOT.jar:?]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:155) ~[paper-api-1.20.1-R0.1-SNAPSHOT.jar:?]
        at org.bukkit.craftbukkit.v1_20_R1.CraftServer.dispatchCommand(CraftServer.java:1007) ~[paper-1.20.1.jar:git-Paper-169]
        at org.bukkit.craftbukkit.v1_20_R1.command.BukkitCommandWrapper.run(BukkitCommandWrapper.java:64) ~[paper-1.20.1.jar:git-Paper-169]
        at com.mojang.brigadier.CommandDispatcher.execute(CommandDispatcher.java:265) ~[paper-1.20.1.jar:?]
        at net.minecraft.commands.Commands.performCommand(Commands.java:324) ~[?:?]
        at net.minecraft.commands.Commands.performCommand(Commands.java:308) ~[?:?]
        at net.minecraft.server.network.ServerGamePacketListenerImpl.performChatCommand(ServerGamePacketListenerImpl.java:2354) ~[?:?]
        at net.minecraft.server.network.ServerGamePacketListenerImpl.lambda$handleChatCommand$21(ServerGamePacketListenerImpl.java:2314) ~[?:?]
        at net.minecraft.util.thread.BlockableEventLoop.lambda$submitAsync$0(BlockableEventLoop.java:59) ~[?:?]
        at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1768) ~[?:?]
        at net.minecraft.server.TickTask.run(TickTask.java:18) ~[paper-1.20.1.jar:git-Paper-169]
        at net.minecraft.util.thread.BlockableEventLoop.doRunTask(BlockableEventLoop.java:153) ~[?:?]
        at net.minecraft.util.thread.ReentrantBlockableEventLoop.doRunTask(ReentrantBlockableEventLoop.java:24) ~[?:?]
        at net.minecraft.server.MinecraftServer.doRunTask(MinecraftServer.java:1338) ~[paper-1.20.1.jar:git-Paper-169]
        at net.minecraft.server.MinecraftServer.d(MinecraftServer.java:197) ~[paper-1.20.1.jar:git-Paper-169]
        at net.minecraft.util.thread.BlockableEventLoop.pollTask(BlockableEventLoop.java:126) ~[?:?]
        at net.minecraft.server.MinecraftServer.pollTaskInternal(MinecraftServer.java:1315) ~[paper-1.20.1.jar:git-Paper-169]
        at net.minecraft.server.MinecraftServer.pollTask(MinecraftServer.java:1308) ~[paper-1.20.1.jar:git-Paper-169]
        at net.minecraft.util.thread.BlockableEventLoop.managedBlock(BlockableEventLoop.java:136) ~[?:?]
        at net.minecraft.server.MinecraftServer.waitUntilNextTick(MinecraftServer.java:1286) ~[paper-1.20.1.jar:git-Paper-169]
        at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1174) ~[paper-1.20.1.jar:git-Paper-169]
        at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:317) ~[paper-1.20.1.jar:git-Paper-169]
        at java.lang.Thread.run(Thread.java:833) ~[?:?]
Caused by: java.lang.NullPointerException: Cannot invoke "java.util.List.size()" because the return value of "java.util.Map.get(Object)" is null
        at io.lumine.mythic.bukkit.commands.mobs.ListActiveCommand.onCommand(ListActiveCommand.java:88) ~[MythicMobs-5.4.0-SNAPSHOT (2).jar:?]
        at io.lumine.mythic.bukkit.utils.commands.Command.onCommand(Command.java:64) ~[MythicMobs-5.4.0-SNAPSHOT (2).jar:?]
        at io.lumine.mythic.bukkit.utils.commands.Command.onCommand(Command.java:55) ~[MythicMobs-5.4.0-SNAPSHOT (2).jar:?]
        at io.lumine.mythic.bukkit.utils.commands.Command.onCommand(Command.java:61) ~[MythicMobs-5.4.0-SNAPSHOT (2).jar:?]
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:45) ~[paper-api-1.20.1-R0.1-SNAPSHOT.jar:?]