As @a_5mith says, You'll need to contact the author to have them update it.
Is this working?
Is this still working on minecraft 1.11.2? I installed a bukkit and nodebb plugin. And put in the ip and api key properly. But it still disconnect.
And there's a error on the console with superperm.
Take a look at mine plugin. Maybe this could be something for you
It uses the minecraft files directly. I intend to rewrite it in the future but it will do for now. It should be compatible with all minecraft server