openinv error

[08:27:37] [Server thread/INFO]: TheOnlyRealTGS issued server command: /openinv FreakyDoodles
[08:27:37] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'openinv' in plugin OpenInv v2.1.9
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[custom.jar:git-Spigot-1571]
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:181) ~[custom.jar:git-Spigot-1571]
	at org.bukkit.craftbukkit.v1_7_R4.CraftServer.dispatchCommand(CraftServer.java:767) ~[custom.jar:git-Spigot-1571]
	at net.minecraft.server.v1_7_R4.PlayerConnection.handleCommand(PlayerConnection.java:1010) [custom.jar:git-Spigot-1571]
	at net.minecraft.server.v1_7_R4.PlayerConnection.a(PlayerConnection.java:847) [custom.jar:git-Spigot-1571]
	at net.minecraft.server.v1_7_R4.PacketPlayInChat.a(PacketPlayInChat.java:28) [custom.jar:git-Spigot-1571]
	at net.minecraft.server.v1_7_R4.PacketPlayInChat.handle(PacketPlayInChat.java:65) [custom.jar:git-Spigot-1571]
	at net.minecraft.server.v1_7_R4.NetworkManager.a(NetworkManager.java:184) [custom.jar:git-Spigot-1571]
	at net.minecraft.server.v1_7_R4.ServerConnection.c(ServerConnection.java:81) [custom.jar:git-Spigot-1571]
	at net.minecraft.server.v1_7_R4.MinecraftServer.v(MinecraftServer.java:731) [custom.jar:git-Spigot-1571]
	at net.minecraft.server.v1_7_R4.DedicatedServer.v(DedicatedServer.java:289) [custom.jar:git-Spigot-1571]
	at net.minecraft.server.v1_7_R4.MinecraftServer.u(MinecraftServer.java:584) [custom.jar:git-Spigot-1571]
	at net.minecraft.server.v1_7_R4.MinecraftServer.run(MinecraftServer.java:490) [custom.jar:git-Spigot-1571]
	at net.minecraft.server.v1_7_R4.ThreadServerApplication.run(SourceFile:628) [custom.jar:git-Spigot-1571]
Caused by: java.lang.NullPointerException
	at com.lishid.openinv.commands.OpenInvPluginCommand.onCommand(OpenInvPluginCommand.java:84) ~[?:?]
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[custom.jar:git-Spigot-1571]
	... 13 more