[23:23:16] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'ccg' in plugin CustomCobbleGen v1.4.5
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:47) ~[patched_1.17.1.jar:git-Paper-406]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:159) ~[patched_1.17.1.jar:git-Paper-406]
        at org.bukkit.craftbukkit.v1_17_R1.CraftServer.dispatchCommand(CraftServer.java:869) ~[patched_1.17.1.jar:git-Paper-406]
        at net.minecraft.server.network.ServerGamePacketListenerImpl.handleCommand(ServerGamePacketListenerImpl.java:2262) ~[app:?]
        at net.minecraft.server.network.ServerGamePacketListenerImpl.handleChat(ServerGamePacketListenerImpl.java:2073) ~[app:?]
        at net.minecraft.server.network.ServerGamePacketListenerImpl.handleChat(ServerGamePacketListenerImpl.java:2054) ~[app:?]
        at net.minecraft.network.protocol.game.ServerboundChatPacket.handle(ServerboundChatPacket.java:46) ~[app:?]
        at net.minecraft.network.protocol.game.ServerboundChatPacket.a(ServerboundChatPacket.java:6) ~[app:?]
        at net.minecraft.network.protocol.PacketUtils.lambda$ensureRunningOnSameThread$1(PacketUtils.java:56) ~[app:?]
        at net.minecraft.server.TickTask.run(TickTask.java:18) ~[patched_1.17.1.jar:git-Paper-406]
        at net.minecraft.util.thread.BlockableEventLoop.doRunTask(BlockableEventLoop.java:149) ~[app:?]
        at net.minecraft.util.thread.ReentrantBlockableEventLoop.doRunTask(ReentrantBlockableEventLoop.java:23) ~[app:?]
        at net.minecraft.server.MinecraftServer.doRunTask(MinecraftServer.java:1426) ~[patched_1.17.1.jar:git-Paper-406]
        at net.minecraft.server.MinecraftServer.executeTask(MinecraftServer.java:192) ~[patched_1.17.1.jar:git-Paper-406]
        at net.minecraft.util.thread.BlockableEventLoop.pollTask(BlockableEventLoop.java:122) ~[app:?]
        at net.minecraft.server.MinecraftServer.pollTaskInternal(MinecraftServer.java:1404) ~[patched_1.17.1.jar:git-Paper-406]
        at net.minecraft.server.MinecraftServer.pollTask(MinecraftServer.java:1397) ~[patched_1.17.1.jar:git-Paper-406]
        at net.minecraft.util.thread.BlockableEventLoop.runAllTasks(BlockableEventLoop.java:110) ~[app:?]
        at net.minecraft.server.MinecraftServer.tickServer(MinecraftServer.java:1536) ~[patched_1.17.1.jar:git-Paper-406]
        at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1282) ~[patched_1.17.1.jar:git-Paper-406]
        at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:319) ~[patched_1.17.1.jar:git-Paper-406]
        at java.lang.Thread.run(Thread.java:831) ~[?:?]
Caused by: java.lang.NullPointerException: Cannot invoke "java.util.UUID.equals(Object)" because the return value of "me.phil14052.CustomCobbleGen.Hooks.BentoboxHook.getIslandLeaderFromPlayer(java.util.UUID)" is null
        at me.phil14052.CustomCobbleGen.Hooks.BentoboxHook.isPlayerLeader(BentoboxHook.java:70) ~[[刷石机]CustomCobbleGen-1.4.5.jar:?]
        at me.phil14052.CustomCobbleGen.GUI.GUIManager$MainGUI.<init>(GUIManager.java:61) ~[[刷石机]CustomCobbleGen-1.4.5.jar:?]
        at me.phil14052.CustomCobbleGen.Commands.MainCommand.onCommand(MainCommand.java:49) ~[[刷石机]CustomCobbleGen-1.4.5.jar:?]
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:45) ~[patched_1.17.1.jar:git-Paper-406]
        ... 21 more

bentobox的岛屿主人获取失败，请问你是在做什么的时候运行的该命令呢？