@Coolnight7
I have also had the city blackout problem for two nights in a row. It always seems to happen when I get to Aceshooter's city while I'm doing my neighborly help thing. I go into his city, and the screen is black other than my two menu screens. World map is fine when I go back to it, and my own city map is fine and usable, but once I hit his city, that one and the ones on the strip to the south that I can click refuse to clear up and go back to normal, even if I f5 and clear cache until approximately ten to fifteen minutes have passed. To note, I usually start at the top of my discovered cities map, and he's the last city on that west-to-east row before I go to the bottom-most row in my discovered range. Once it clears though, everything goes back to normal and I can click and collect on his and the other remaining cities.