nodrop enable

[12:02:10] [Server thread/WARN]: Unexpected exception while parsing console command "nodrop enable"
org.bukkit.command.CommandException: Unhandled exception executing command 'nodrop' in plugin NoDrop v1.4
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot-1.7.9-R0.1-SNAPSHOT.jar:git-Spigot-1451]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:180) ~[spigot-1.7.9-R0.1-SNAPSHOT.jar:git-Spigot-1451]
        at org.bukkit.craftbukkit.v1_7_R3.CraftServer.dispatchCommand(CraftServer.java:722) ~[spigot-1.7.9-R0.1-SNAPSHOT.jar:git-Spigot-1451]
        at org.bukkit.craftbukkit.v1_7_R3.CraftServer.dispatchServerCommand(CraftServer.java:709) [spigot-1.7.9-R0.1-SNAPSHOT.jar:git-Spigot-1451]
        at net.minecraft.server.v1_7_R3.DedicatedServer.aB(DedicatedServer.java:319) [spigot-1.7.9-R0.1-SNAPSHOT.jar:git-Spigot-1451]
        at net.minecraft.server.v1_7_R3.DedicatedServer.v(DedicatedServer.java:284) [spigot-1.7.9-R0.1-SNAPSHOT.jar:git-Spigot-1451]
        at net.minecraft.server.v1_7_R3.MinecraftServer.u(MinecraftServer.java:576) [spigot-1.7.9-R0.1-SNAPSHOT.jar:git-Spigot-1451]
        at net.minecraft.server.v1_7_R3.MinecraftServer.run(MinecraftServer.java:482) [spigot-1.7.9-R0.1-SNAPSHOT.jar:git-Spigot-1451]
        at net.minecraft.server.v1_7_R3.ThreadServerApplication.run(SourceFile:628) [spigot-1.7.9-R0.1-SNAPSHOT.jar:git-Spigot-1451]
Caused by: java.lang.ClassCastException: org.bukkit.craftbukkit.v1_7_R3.command.ColouredConsoleSender cannot be cast to org.bukkit.entity.Player
        at me.fred12i12i.NoDrop.NoDrop.onCommand(NoDrop.java:38) ~[?:?]
        at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spigot-1.7.9-R0.1-SNAPSHOT.jar:git-Spigot-1451]
        ... 8 more