Just started playing the game and for some reason I can't tell where my units are. The outline only shows if I click on the unit, but even then, I can't see the actual model. I basically have to guess where my units are located and then watch an empty blue hex move across the map.
My laptop is running on an Intel Core i5 processor with 6 GB of RAM. It's admittedly a bit slow, but I've never had any real issues playing Civ 5.