[SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'rankup' in plugin CommandRank v3.1.9
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46)
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:192)
	at org.bukkit.craftbukkit.v1_6_R3.CraftServer.dispatchCommand(CraftServer.java:523)
	at net.minecraft.server.v1_6_R3.PlayerConnection.handleCommand(PlayerConnection.java:959)
	at net.minecraft.server.v1_6_R3.PlayerConnection.chat(PlayerConnection.java:877)
	at net.minecraft.server.v1_6_R3.PlayerConnection.a(PlayerConnection.java:834)
	at net.minecraft.server.v1_6_R3.Packet3Chat.handle(SourceFile:49)
	at net.minecraft.server.v1_6_R3.NetworkManager.b(NetworkManager.java:296)
	at net.minecraft.server.v1_6_R3.PlayerConnection.e(PlayerConnection.java:116)
	at net.minecraft.server.v1_6_R3.ServerConnection.b(SourceFile:37)
	at net.minecraft.server.v1_6_R3.DedicatedServerConnection.b(SourceFile:30)
	at net.minecraft.server.v1_6_R3.MinecraftServer.t(MinecraftServer.java:592)
	at net.minecraft.server.v1_6_R3.DedicatedServer.t(DedicatedServer.java:227)
	at net.minecraft.server.v1_6_R3.MinecraftServer.s(MinecraftServer.java:488)
	at net.minecraft.server.v1_6_R3.MinecraftServer.run(MinecraftServer.java:421)
	at net.minecraft.server.v1_6_R3.ThreadServerApplication.run(SourceFile:583)
Caused by: java.lang.ArrayIndexOutOfBoundsException: 1
	at org.black_ixx.commandRank.rankUpTypes.CommandRankUp.getNextRankUp(CommandRankUp.java:38)
	at org.black_ixx.commandRank.rankUpTypes.CommandRankUp.tryRankUp(CommandRankUp.java:17)
	at org.black_ixx.commandRank.commands.CommandRankUp.onCommand(CommandRankUp.java:31)
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
	... 15 more