Specific plugin does not work in my server. [ChangeSkin]

So... Recently I have been getting bored from disguising myself and only the server can see it, I wanted to install a skin changer plugin of some sorts, but it is not working for some reason. I have installed the right version, reloaded several times and its not working. I also restarted and it's still not appearing in anything on the plugins or logs. Most versions are quite universal though, I'm using 1.8 because I really have a hatred for the combat update. I really do want this plugin but it's just not working. Does anyone know why? (Yes i have tried installing another plugin and it worked.)

Alright, turns out I actually needed ProtocolLib for it to even work at all. Whoops!