You can do an if statement to see if the player is flying and if he is then set his flying mode to false.
I looked in the essentials command reference: You just need to remove this permission from the group and it should work
In the PlayerJoinEvent it needs to be player.setAllowFlight(false); player.setFlying(false); both of them not just player.setAllowFlight(false);
Code: @EventHandler public void DisableFlight(PlayerJoinEvent e){ Player p = e.getPlayer(); p.setFlying(false); p.setAllowFlight(false); }