I made the mistake of leaving Arcadia's Cauldron during daylight hours when she was speaking to me, and she left too, to finish her dialog.
Naturally, she locked the door in the process.
After repeating the dialog, she returned to her store… except the door is locked.
Picking the lock doesn't fix the problem: she complains I'm trespassing and I can't shop with her.
How do I fix this?
Best Answer
In cases where daily NPC tasks get muddled with (often due to Dragonborn interference); as long as the prerequisite NPCs haven't been killed, and there isn't a quest or mod interfering with their schedule - they can be put back on track by waiting a few in-game hours (sometimes waiting a full 24 hours is necessary).
This does not necessarily mean standing around hearing the guards repeatedly tell you about their arrow related knee injuries. Skyrim has a few built in methods to quickly advance time by hours. Pressing the T key on PC (I believe it's the Back button on Xbox) will bring up the a window that lets you set how many hours you wish to wait. You can also use beds - which may mean either owning a house in the city or paying the inn to rest in a bed. You could also potentially use quick travel to go to a far corner of Skyrim and then quick travel back to advance the clock a number of hours.
Using the wait function to advance just an hour or two should cause the town to reset its self to whatever state it should be in at that particular time. Failing that, waiting a full 24 hours should often do the trick.