Bukkit

What steps will reproduce the problem?
Hello,
I'm trying to enter the command "/playerskin" and it says that it doesn't recognize this command.
It's not just this command, it's all the commands of this plugin...

What is the expected output? What do you see instead?
The expected output is that the skin of a player or citizen will be changed.
Instead of that, The console says that this command isn't recognized by the server.

What version of the product are you using?
The latest, v2.4.

Do you have an error log of what happened?
Nope, There is no error log.