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bác ơi chỉ tui fix lỗi này vs
và trong run.bat như sau
[18:45:15 ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'lordland' in plugin LORDLAND v0.1
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot.jar:git-Spigot-596221b-9a1fc1e]
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[spigot.jar:git-Spigot-596221b-9a1fc1e]
at org.bukkit.craftbukkit.v1_12_R1.CraftServer.dispatchCommand(CraftServer.java:641) ~[spigot.jar:git-Spigot-596221b-9a1fc1e]
at net.minecraft.server.v1_12_R1.PlayerConnection.handleCommand(PlayerConnection.java:1385) [spigot.jar:git-Spigot-596221b-9a1fc1e]
at net.minecraft.server.v1_12_R1.PlayerConnection.a(PlayerConnection.java:1220) [spigot.jar:git-Spigot-596221b-9a1fc1e]
at net.minecraft.server.v1_12_R1.PacketPlayInChat.a(PacketPlayInChat.java:45) [spigot.jar:git-Spigot-596221b-9a1fc1e]
at net.minecraft.server.v1_12_R1.PacketPlayInChat.a(PacketPlayInChat.java:1) [spigot.jar:git-Spigot-596221b-9a1fc1e]
at net.minecraft.server.v1_12_R1.PlayerConnectionUtils$1.run(SourceFile:13) [spigot.jar:git-Spigot-596221b-9a1fc1e]
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_231]
at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_231]
at net.minecraft.server.v1_12_R1.SystemUtils.a(SourceFile:46) [spigot.jar:git-Spigot-596221b-9a1fc1e]
at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:747) [spigot.jar:git-Spigot-596221b-9a1fc1e]
at net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:405) [spigot.jar:git-Spigot-596221b-9a1fc1e]
at net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:678) [spigot.jar:git-Spigot-596221b-9a1fc1e]
at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:576) [spigot.jar:git-Spigot-596221b-9a1fc1e]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_231]
Caused by: java.lang.NullPointerException
at THUANPHAT.Commands.LordLandCommands.onCommand(LordLandCommands.java:17) ~[?

]
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spigot.jar:git-Spigot-596221b-9a1fc1e]
... 15 more