Where did you install it? It's designed to be put into the CustomAssets folder.
edit: Hmm, just noticed I accidentally included a CvScreensInterface.py file that shouldn't be included (it's from another mod). Try deleting that file and see if it works.
I'm trying to balance the RPs that you get for capping. Right now I was thinking about going with:
CS x 5 + rand(CS x 10)
where CS = city size / 4
So a size 10 city, for example would be CS = 2 (always rounds down), giving
10 + rand(20) or 10-30% of the RPs for a tech.
Dunno if people think that's too low? A size 20 city would be 25-75%, which is what it's at now.
Bh