[01:21:16] [Server thread/INFO]: wksjim issued server command: /rankup
[01:21:16] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'rankup' in plugin Rankup v3.5.5
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:48) ~[spigot.1.13.2.jar:git-Spigot-1a3504a-dfa7583]
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[spigot.1.13.2.jar:git-Spigot-1a3504a-dfa7583]
	at org.bukkit.craftbukkit.v1_13_R2.CraftServer.dispatchCommand(CraftServer.java:704) ~[spigot.1.13.2.jar:git-Spigot-1a3504a-dfa7583]
	at net.minecraft.server.v1_13_R2.PlayerConnection.handleCommand(PlayerConnection.java:1621) ~[spigot.1.13.2.jar:git-Spigot-1a3504a-dfa7583]
	at net.minecraft.server.v1_13_R2.PlayerConnection.a(PlayerConnection.java:1461) ~[spigot.1.13.2.jar:git-Spigot-1a3504a-dfa7583]
	at net.minecraft.server.v1_13_R2.PacketPlayInChat.a(PacketPlayInChat.java:45) ~[spigot.1.13.2.jar:git-Spigot-1a3504a-dfa7583]
	at net.minecraft.server.v1_13_R2.PacketPlayInChat.a(PacketPlayInChat.java:1) ~[spigot.1.13.2.jar:git-Spigot-1a3504a-dfa7583]
	at net.minecraft.server.v1_13_R2.PlayerConnectionUtils.lambda$0(PlayerConnectionUtils.java:9) ~[spigot.1.13.2.jar:git-Spigot-1a3504a-dfa7583]
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_111]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_111]
	at net.minecraft.server.v1_13_R2.SystemUtils.a(SourceFile:199) [spigot.1.13.2.jar:git-Spigot-1a3504a-dfa7583]
	at net.minecraft.server.v1_13_R2.MinecraftServer.b(MinecraftServer.java:896) [spigot.1.13.2.jar:git-Spigot-1a3504a-dfa7583]
	at net.minecraft.server.v1_13_R2.DedicatedServer.b(DedicatedServer.java:417) [spigot.1.13.2.jar:git-Spigot-1a3504a-dfa7583]
	at net.minecraft.server.v1_13_R2.MinecraftServer.a(MinecraftServer.java:831) [spigot.1.13.2.jar:git-Spigot-1a3504a-dfa7583]
	at net.minecraft.server.v1_13_R2.MinecraftServer.run(MinecraftServer.java:729) [spigot.1.13.2.jar:git-Spigot-1a3504a-dfa7583]
	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_111]
Caused by: java.lang.NullPointerException
	at sh.okx.rankup.RankList.getFirst(RankList.java:55) ~[?:?]
	at sh.okx.rankup.RankList.getOrderedList(RankList.java:67) ~[?:?]
	at sh.okx.rankup.RankList.getByPlayer(RankList.java:88) ~[?:?]
	at sh.okx.rankup.commands.RankupCommand.onCommand(RankupCommand.java:34) ~[?:?]
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot.1.13.2.jar:git-Spigot-1a3504a-dfa7583]
	... 15 more