error after /sentinel addtarget monsters

←[31;1m[15:45:09 ERROR]: Command exception: /sentinel addtarget monsters
org.bukkit.command.CommandException: Unhandled exception executing command 'sentinel' in plugin Sentinel v2.9.2-SNAPSHOT (build 527)
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:47) ~[paper-api-1.21.11-R0.1-SNAPSHOT.jar:?]
        at io.papermc.paper.command.brigadier.bukkit.BukkitCommandNode$BukkitBrigCommand.run(BukkitCommandNode.java:83) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at com.mojang.brigadier.context.ContextChain.runExecutable(ContextChain.java:73) ~[brigadier-1.3.10.jar:?]
        at net.minecraft.commands.execution.tasks.ExecuteCommand.execute(ExecuteCommand.java:30) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.commands.execution.tasks.ExecuteCommand.execute(ExecuteCommand.java:13) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.commands.execution.UnboundEntryAction.lambda$bind$0(UnboundEntryAction.java:8) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.commands.execution.CommandQueueEntry.execute(CommandQueueEntry.java:5) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.commands.execution.ExecutionContext.runCommandQueue(ExecutionContext.java:104) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.commands.Commands.executeCommandInContext(Commands.java:469) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.commands.Commands.performCommand(Commands.java:374) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.commands.Commands.performCommand(Commands.java:362) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.server.network.ServerGamePacketListenerImpl.performUnsignedChatCommand(ServerGamePacketListenerImpl.java:2375) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.server.network.ServerGamePacketListenerImpl.lambda$handleChatCommand$12(ServerGamePacketListenerImpl.java:2348) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.server.TickTask.run(TickTask.java:18) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.util.thread.BlockableEventLoop.doRunTask(BlockableEventLoop.java:177) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.util.thread.ReentrantBlockableEventLoop.doRunTask(ReentrantBlockableEventLoop.java:24) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.server.MinecraftServer.doRunTask(MinecraftServer.java:1525) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.server.MinecraftServer.doRunTask(MinecraftServer.java:188) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.util.thread.BlockableEventLoop.pollTask(BlockableEventLoop.java:151) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.server.MinecraftServer.pollTaskInternal(MinecraftServer.java:1505) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.server.MinecraftServer.pollTask(MinecraftServer.java:1499) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.server.MinecraftServer.recordTaskExecutionTimeWhileWaiting(MinecraftServer.java:1225) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1341) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at net.minecraft.server.MinecraftServer.lambda$spin$2(MinecraftServer.java:388) ~[paper-1.21.11.jar:1.21.11-132-c5eb079]
        at java.base/java.lang.Thread.run(Thread.java:1516) ~[?:?]
Caused by: java.lang.NullPointerException: Cannot invoke "java.lang.reflect.Field.get(Object)" because "org.mcmonkey.sentinel.commands.SentinelCommand.commandInfoMethodField" is null
        at Sentinel-2.9.2-SNAPSHOT-b527.jar//org.mcmonkey.sentinel.commands.SentinelCommand.isSentinelRequired(SentinelCommand.java:90) ~[?:?]
        at Sentinel-2.9.2-SNAPSHOT-b527.jar//org.mcmonkey.sentinel.commands.SentinelCommand.onCommand(SentinelCommand.java:140) ~[?:?]
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:45) ~[paper-api-1.21.11-R0.1-SNAPSHOT.jar:?]
        ... 24 more