Here's
another thread with the same missing quest-NPCs problem.
Let me stress that in my case it's not a second rank problem. It's absolutely massive, probably the biggest, most annoying quest bug I've ever seen in an RPG. It's highly de-motivating because the reward for hours of action is missing - repeatedly.
Whole quest lines have been closed because the key NPCs either didn't spawn (I suppose) or spawned in the wrong place (confirmed for the Alrik NPC). For example I couldn't complete most of the dragon tower quests and therefore didn't get most of the upgrades. Ulthrand's amrour is also incomplete because at least one of the boss opponents was missing. I even got stuck in a locked room without end boss and had to reload (-> fortress -> final room -> in 4 corners enemies are endlessly spawned).
The first time I ran into it was the cave with Ragon in it. The bandit which was supposed to have the key for the left side of the cave wasn't there. Dead end, Ragon was safe behind a force field.
With a bit of luck I may still have a savegame right before I enter that cave, if you think it could be helpful.
German game plus add-on, btw. Both installed directly from the retail disks. No patches except what was automatically applied.
edit:
It started much earlier than level 30 for me.
