When you install your humidifier, make sure you press firm and hard on the metallic plate for two minutes to assure a tight bond. If this is not done, the humidifier might fall off. If your humidifier still falls loose then you can try re-applying using a hot glue gun or any other non-odor emitting glue. Once this is done you can replace the unit and enjoy your smokes.
HOW DO I GET MY HUMIDIFIER TO STICK ON THE HUMIDOR? by David Sabot