23:53:48 INFO]: BOOMER_1 issued server command: /duel
[23:53:51 INFO]: BOOMER_1 issued server command: /duel leave
[23:53:57 INFO]: BOOMER_1 issued server command: /duel decline
[23:53:57 ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'duel' in plugin McDuels v16.6.2
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:47) ~[duels.jar:git-TacoSpigot-bf023c7d]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:143) ~[duels.jar:git-TacoSpigot-bf023c7d]
        at org.bukkit.craftbukkit.v1_8_R3.CraftServer.dispatchCommand(CraftServer.java:667) ~[duels.jar:git-TacoSpigot-bf023c7d]
        at net.minecraft.server.v1_8_R3.PlayerConnection.handleCommand(PlayerConnection.java:1178) [duels.jar:git-TacoSpigot-bf023c7d]
        at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:991) [duels.jar:git-TacoSpigot-bf023c7d]
        at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(PacketPlayInChat.java:45) [duels.jar:git-TacoSpigot-bf023c7d]
        at net.minecraft.server.v1_8_R3.PacketPlayInChat.a(PacketPlayInChat.java:1) [duels.jar:git-TacoSpigot-bf023c7d]
        at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [duels.jar:git-TacoSpigot-bf023c7d]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_201]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_201]
        at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [duels.jar:git-TacoSpigot-bf023c7d]
        at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:785) [duels.jar:git-TacoSpigot-bf023c7d]
        at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:427) [duels.jar:git-TacoSpigot-bf023c7d]
        at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:724) [duels.jar:git-TacoSpigot-bf023c7d]
        at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:627) [duels.jar:git-TacoSpigot-bf023c7d]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_201]
Caused by: java.lang.ArrayIndexOutOfBoundsException: 1
        at me.stevie212.McDuels.Commands.Core.onCommand(Core.java:60) ~[?:?]
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:45) ~[duels.jar:git-TacoSpigot-bf023c7d]
        ... 15 more