Having this issue too. I played Thursday night just fine and was able to move my Sims between worlds and enter build mode etc with no problem. Today in a separate save I moved a sim into a lot then tried to place a build from the gallery. It got stuck in the loading screen. I had to force quit. Then I went back in and tried to place a lot from the world map and it got stuck in the loading screen. I closed and tried again by entering the lot itself to build and it got stuck entering the lot. I closed and tried a different save with the same results. I also deleted the few pieces of CC I downloaded between last night and tonight with the same results. I've deleted my thumbcache and repaired my game. I also noticed when I'm loading into a lot to play not to build it takes a long time but it does eventually load.
