Casino Error

20:20:23 [SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'casi
no' in plugin AnCasino v2.1.1
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:42)
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:16
6)
        at org.bukkit.craftbukkit.CraftServer.dispatchCommand(CraftServer.java:4
73)
        at net.minecraft.server.NetServerHandler.handleCommand(NetServerHandler.
java:821)
        at net.minecraft.server.NetServerHandler.chat(NetServerHandler.java:781)

        at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:764)
        at net.minecraft.server.Packet3Chat.handle(Packet3Chat.java:33)
        at net.minecraft.server.NetworkManager.b(NetworkManager.java:229)
        at net.minecraft.server.NetServerHandler.a(NetServerHandler.java:113)
        at net.minecraft.server.NetworkListenThread.a(NetworkListenThread.java:7
8)
        at net.minecraft.server.MinecraftServer.w(MinecraftServer.java:554)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:452)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:490)
Caused by: java.lang.NullPointerException
        at org.bukkit.craftbukkit.CraftServer.getPlayer(CraftServer.java:294)
        at com.earth2me.essentials.api.Economy.getUserByName(Economy.java:76)
        at com.earth2me.essentials.api.Economy.getMoney(Economy.java:96)
        at com.earth2me.essentials.api.Economy.hasEnough(Economy.java:204)
        at net.milkbowl.vault.economy.plugins.Economy_Essentials.has(Economy_Ess
entials.java:215)
        at me.darazo.ancasino.command.CasinoAddManaged.process(CasinoAddManaged.
java:64)
        at me.darazo.ancasino.command.AnCommandExecutor.onCommand(AnCommandExecu
tor.java:111)
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:40)
        ... 12 more