[12:33:23] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'estv' in plugin EssentialsTiengViet v0.1
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot.jar:git-Spigot-dcd1643-d7bebef]
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[spigot.jar:git-Spigot-dcd1643-d7bebef]
	at org.bukkit.craftbukkit.v1_12_R1.CraftServer.dispatchCommand(CraftServer.java:648) ~[spigot.jar:git-Spigot-dcd1643-d7bebef]
	at net.minecraft.server.v1_12_R1.PlayerConnection.handleCommand(PlayerConnection.java:1399) [spigot.jar:git-Spigot-dcd1643-d7bebef]
	at net.minecraft.server.v1_12_R1.PlayerConnection.a(PlayerConnection.java:1234) [spigot.jar:git-Spigot-dcd1643-d7bebef]
	at net.minecraft.server.v1_12_R1.PacketPlayInChat.a(PacketPlayInChat.java:45) [spigot.jar:git-Spigot-dcd1643-d7bebef]
	at net.minecraft.server.v1_12_R1.PacketPlayInChat.a(PacketPlayInChat.java:1) [spigot.jar:git-Spigot-dcd1643-d7bebef]
	at net.minecraft.server.v1_12_R1.PlayerConnectionUtils$1.run(SourceFile:13) [spigot.jar:git-Spigot-dcd1643-d7bebef]
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_261]
	at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_261]
	at net.minecraft.server.v1_12_R1.SystemUtils.a(SourceFile:46) [spigot.jar:git-Spigot-dcd1643-d7bebef]
	at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:748) [spigot.jar:git-Spigot-dcd1643-d7bebef]
	at net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:406) [spigot.jar:git-Spigot-dcd1643-d7bebef]
	at net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:679) [spigot.jar:git-Spigot-dcd1643-d7bebef]
	at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:577) [spigot.jar:git-Spigot-dcd1643-d7bebef]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_261]
Caused by: java.lang.ArrayIndexOutOfBoundsException: 0
	at CauLenh.TrungTamLenh.onCommand(TrungTamLenh.java:83) ~[?:?]
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spigot.jar:git-Spigot-dcd1643-d7bebef]
	... 15 more