While going through the "Creepy Crypt" level, I found the exit out of the dungeon part of the level without completing the current quest. Even though there was a border blocking me from going through it I just happened to press "A" with curiosity and ended up going through the exit. Upon reentering the dungeon, I could not get back in all the way without the barrier blocking me.

The main problem was that even though I was able to get through the dungeon exit without finishing my current quest, I was not able to "exit" the whole level and complete it. This meant that my only option was to return back to camp and redo the level all over again (I still kept all my loot that I gained though).