I am having the same problem. I have the gold edition which only gave me one serial number which registers as Dark Avatar. When I try to play Twilight it say Avatar needs to be updated. When I try to update Avatar it says GalCiv2 is not registered. I put in my ONE serial number no luck. I point to directory for browse option no luck. How can this be resolved?
The game edtion is GaLCiv2 gold. I downloaded Arnor from IMpulse.
Machine is Dell XPS 630i OS is Vista sp1, 4G RAM updates are current
Video is Nvidia 9600GT