I've unlocked the final tier in empire building, but I cannot build Obelisks. They don't even show up in my system build lists. 

The game has actually gotten super-buggy since I switched to 1.0.5. I was offered the opportunity to recruit a hero that I had already recruited--during the finale of the Academy quest, no less, when hero recruitment is supposed to be locked. My capital somehow got switched to building something that it has already built, which shut down the build queue until I manually removed the offending improvement. 

Also, the entire population section (along with the button to open the population management screen) has vanished from the Government screen. It's just... gone.