There is currently a different sort of bug for the main story quest "The Weight of Three Crowns" other than the usual "alliance leaders do not spawn" people usually have. This is not exactly progression blocking, but it it does ruin the experience considerably by eliminating a lot of dialogue, backstory and information. It used to be working fine:
Currently, the NPC's Lady Laurent, Telenger, and Captain Alphaury do not spawn (neither do any of the other NPC's in the guild camps out front). There are waypoints to their locations but they are not there. Vanus talks to them but they do not talk back (since they are not there). These are a pretty significant part of the experience of the quest with a lot of dialogue. Also, people may waste time looking for these non-existent NPC's.
This used to be working fine because I did this quest 2 months ago on another character and all these NPC's were present and functioning properly.