Users who joined will not be registered as premium until they do the /premium command. They will be kicked and they have to rejoin in 1 minute for the plugin to register them as premium. If they can't join during that 1 minute and keep getting NullPointerExceptions when they try to join, then it means that they are not premium. If they successfully join, then they will be registered as premium.

Also added /unpremium command if they choose to unregister their account as not premium. It will kick them and revert them back to cracked.

Do note that BungeeCord is the more supported version, if you have BungeeCord enabled then the Bukkit/Spigot version will not be used if you have it on the Bukkit servers.

For developers: If you want to register your user as premium, a plugin message channel will be sent whenever a user joins as a premium account. UUID of premium users will still be their Offline UUID instead of their Online UUID, do take note!