Taelia Missing for Boralus Quests

Most phasing problems in Boralus, including issues with Taelia being absent for quests, are caused by one starting but not completing one of the following three quest lines:

• The introductory questline for Boralus. If you have completed the quest A Local Guide but have not accepted the follow-up quest from Flynn Fairwind, An Explosive Entrance, Taelia will remain phased out for other quests.
• The quest line to unlock the Kul Tiran allied race. If you have started or completed the quest Made in Kul Tiras but have not completed the entire quest line, you must complete it to proceed. 
• The Pride of Kul Tiras quest line. Starting this quest line can cause phasing which can prevent you from being able to hand in A New Dawn. To resolve the issue, finish the quest line.