I've never installed any mods since I didn't really begin playing until the latest patch. It's as clean an installation as you can get. But this is not the only problem I'm seeing. Occasionally the names of cities get mixed up - for instance the purple guy in my campaign is in a city named Altos and my capital is called Veanlu, but it says Altos over my capital AND his city.
Even worse, which just now happened, the game will not proceed to the next turn! I even realoaded from an auto save a few turns back and every time I get to Winter 243 AC the End Turn button does nothing at all, and after I click it the game stops responding. I can still pan around the map and select things but nothing else works. I was really hoping to finally get into this game after buying it on launch day and waiting so long for 1.1... but I guess my luck sucks. I really hope Stardock can solve my problem, else I will lose faith completely... 
Also the game still has quite a few typos. Can they not have someone literate sit down and go over every piece of text? Becuase when thigns arent spelled corectly... well you see how it looks 