I looked at tutorials to figure out how to register permission nodes in plugin.yml and child nodes and all that worked, but a user of my plugin told me that permission nodes were not working for them. They use Essentials Group Manager. I saw PluginManager.addPermission() but do not know if this is necessary on top of registering via plugin.yml, nor does the JavaDoc for the method mention this. My uncertainty is also magnified by the fact that this is the first time someone has mentioned a permission bug, in the half year my plugin has been out. If someone could just clarify this for me, it would be much appreciated.