My Pirate Dragon, Carnivore Dragon, and Zombie Dragon were inhabiting in the Dungeon Docking Habitat before. These dragons were not stored in my storage right after the transition of facebook to mobile app changes. Due to this, these dragons causes my game to crash everytime I use them in finding tower pieces and breeding.
Furthermore, I theorized that the bug in my breeding sanctuary was because of my Pirate Dragon. My Pirate Dragon was on breeding status before the transition changes happened. Now that I reinstalled the game, everytime I click my breeding sanctuary (the breeding is complete), the game crashes. Due to this, I cannot use my breeding sanctuary nor my other dragons inhabiting the dungeon (Carnivore and Zombie).