SureAI

I'm supposed to meet Jespar at the inn after getting the stone and I'm getting the message that the lock won't open without a key. The inn is open, no message of key difficulty, etc.

Have you tried an earlier save first and see if you can reproduce the bug?

If I recall, he's not actually in the inn itself, but on a balcony or bridge which you can only access from the second floor of the inn. And yes, I believe you can only open the door to that balcony/bridge after having gotten the stone.

Is this the door that's causing you problems? (As an aside, I suppose you've checked to see if the stone is actually in your inventory?)

Right. He has to visit all three locations with the coded notes from Jespar's sister. If he finished all the letters then the door should open for him. The stone comes after not before. After you speak to Jespar about the notes then he leads you to his sister who has the black stone.

Erm, Every Day like the last IV is the part where you already have the Dal'Varek-stone. You've to speak to the innkeeper who directs you to some taverns where in the last one you'll find Jespar.

Otherwise, but then it's not part IV, you'll have to solve all the clues from Jespar's package before the balcony opens.

Yeah, EM is right. This is after I had the stones. As it happens my last hard save was hours back so tried forcing it forward. I did the next main quest, Black Light part 2. After that the door fixed itself again so now i can do his quest while the MQ waits for me to get some rest.

For the record it was the main doors into the inn. Neither would let me in but it's fixed now.

All doors in Ark are inaccessible during the attack. It's scripted. One can't even switch between the quarters. After this day everything's normal again.

I guess that;s the reason for it but still seems buggy one way or the other.

When I put the last stone, but before I went and triggered the battle, I had a quest open for each of Jespar and Calia. I entered the Sun Temple and had my dialogue with Calia, finishing that phase of her quest. Then I went to the inn but I could not enter. Again, I had not triggered the battle and, in fact, had no idea it was about to happen.

Is the sun temple an exception to Ark being locked down? Is it because I left the Temple district?

Seems a bit too early for the shutdown. Maybe really a bug.
My usual route is after handing over the three stones (before talking to anyone else) visiting Calia and immediately afterwards searching for Jespar. Til yet I had no problems.

Well, that was my plan. Didn't quite work out that way.