Version of Game: 0.76 (so this might have been fixed in 0.77).

I don't know if writing the quest conditions are spoilers, but for the sake of bug reporting, I'll just assume it doesn't matter. I have a hunch that perhaps there was a problem placing the Dragon part of the quest onto the map due to collision problems (although I might be wrong).

Description of conditions in the game

• I got the Cloak of Stars quest deep in the middle of my territory and surrounded by lots of my own stuff (see image below, and attached save game).
• The Ophidian lairs appeared on the map.
• I already had lots of crystals so the next turn the quest moved on to stage to before I even reached an ophidian lair.
• I accepted the next part of the quest, but try as I might over lots of retries, I can't find the Dragon Lair located on any portion of my map. The quest XML says it should be placed in a radius of 12 (not sure I'm interpreting it correctly), but I looked all over the map in a radius of 12 from the quest origin and couldn't find the lair.

Link to save game, I believe just before I start the quest.

save game

Sample image of the area below