Hello All, this is my first time posting but I've been playing GalCiv2 for a while.
I have a problem on my current game that's extremely vexing: Playing as Arceans in Ultimate Edition v2.03, Challenging difficulty, I already controlled about half the map and was halfway into culturally absorbing the Thalans (who are trying ot ascend). Then I get hit by the Jagged Knife event, loosing 14 planet. No sweat, I think, I'll just retake them, along with all the planets the AI lost. So the invasions are turning to be a slog since the JK has the same soldiering that I do, so I start using Tidal Disruptors in my invasions. I've retaken 2 worlds already, but I find out both of them are missing their Adv. Navigation Center, and I get no option ot rebuild! Is this a bug? Becasuse those 2 were Industrial centers focused on Ship building. I was planning on taking out the JK before ending the game, but if that is how's it going to be then I'd rather end now via Diplomatic Victory. 
