Hey there,
some things you should try are removing the plugin, and getting an up to date version of it. Try reloading the server with /reload and do /plugins to see if it is active. Once that it ready follow the enjin tutorial to link your server!
Regards,
~ PanicPenguin
Let me just add to that:
You should never use the /reload command.. If you have a server with 10+ plugin it can break every single one of them and cause unnecessary corruption / lag. If you don't want to go through the entire process of clicking a button to restart your server, you can always install a plugin called Plugman and type /plugman reload {yourpluginname}.
Hope I helped a little, I know this is quite off-topic but I've had troubles with the /reload command in the past and I like helping out fellow minemen
Infixes