My Quest is Stuck

For the vast majority of quests, it is safe to delete them from your active quest lists and restart them.

The ones which are not include:

• Quests in the Burning Archer Series
•  Dralnok's Doom (Chapter 2): The Hammer of Kings

Most others can be restarted and worked through from the start again.

As a special note, if a quest requires you to have a certain item, that item must be in your character's main inventory.  It can not be stored in the vault, on a plot, or in a pouch somewhere.  The particular NPC you are speaking to must be able to "find" the item in the main inventory in order to delete it.