Bukkit

Latest free version.
Java 8
Minecraft 1.9.2

This is what I am using. Trying to send it through RCON, this is my error. I think the anser lies here.

"03.05 02:53:34 [Server] INFO Caused by: java.lang.ClassCastException: org.bukkit.craftbukkit.v1_9_R1.command.CraftRemoteConsoleCommandSender cannot be cast to org.bukkit.entity.Player"

Full error:

03.05 02:53:34 [Server] INFO ... 11 more
03.05 02:53:34 [Server] INFO at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[custom18.jar:git-Spigot-f6feaaa-f326992]
03.05 02:53:34 [Server] INFO at cratereloaded.aL.onCommand(CommandManager.java:101) ~[?:?]
03.05 02:53:34 [Server] INFO at cratereloaded.bf.has(PermissionUtil.java:18) ~[?:?]
03.05 02:53:34 [Server] INFO Caused by: java.lang.ClassCastException: org.bukkit.craftbukkit.v1_9_R1.command.CraftRemoteConsoleCommandSender cannot be cast to org.bukkit.entity.Player
03.05 02:53:34 [Server] INFO at java.lang.Thread.run(Thread.java:745) [?:1.8.0_66]
03.05 02:53:34 [Server] INFO at net.minecraft.server.v1_9_R1.MinecraftServer.run(MinecraftServer.java:559) [custom18.jar:git-Spigot-f6feaaa-f326992]
03.05 02:53:34 [Server] INFO at net.minecraft.server.v1_9_R1.MinecraftServer.C(MinecraftServer.java:660) [custom18.jar:git-Spigot-f6feaaa-f326992]
03.05 02:53:34 [Server] INFO at net.minecraft.server.v1_9_R1.DedicatedServer.D(DedicatedServer.java:400) [custom18.jar:git-Spigot-f6feaaa-f326992]
03.05 02:53:34 [Server] INFO at net.minecraft.server.v1_9_R1.MinecraftServer.D(MinecraftServer.java:735) [custom18.jar:git-Spigot-f6feaaa-f326992]
03.05 02:53:34 [Server] INFO at org.bukkit.craftbukkit.v1_9_R1.util.Waitable.run(Waitable.java:24) [custom18.jar:git-Spigot-f6feaaa-f326992]
03.05 02:53:34 [Server] INFO at net.minecraft.server.v1_9_R1.DedicatedServer$5.evaluate(DedicatedServer.java:1) [custom18.jar:git-Spigot-f6feaaa-f326992]
03.05 02:53:34 [Server] INFO at net.minecraft.server.v1_9_R1.DedicatedServer$5.evaluate(DedicatedServer.java:688) [custom18.jar:git-Spigot-f6feaaa-f326992]
03.05 02:53:34 [Server] INFO at org.bukkit.craftbukkit.v1_9_R1.CraftServer.dispatchServerCommand(CraftServer.java:631) [custom18.jar:git-Spigot-f6feaaa-f326992]
03.05 02:53:34 [Server] INFO at org.bukkit.craftbukkit.v1_9_R1.CraftServer.dispatchCommand(CraftServer.java:645) ~[custom18.jar:git-Spigot-f6feaaa-f326992]
03.05 02:53:34 [Server] INFO at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) ~[custom18.jar:git-Spigot-f6feaaa-f326992]
03.05 02:53:34 [Server] INFO at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[custom18.jar:git-Spigot-f6feaaa-f326992]
03.05 02:53:34 [Server] INFO org.bukkit.command.CommandException: Unhandled exception executing command 'crate' in plugin CrateReloaded v1.3.25
03.05 02