Can't visit friend's towns despite them updating

RSommons wrote:
When in doubt. Reboot. Or at least leave the app, close it from the menu and try again. Only guessing.

I've closed it and rebooted twice - nothing. I'm thinking that when you get the update you have to close it annd restart it before your friends can visit you. I had closed the game and when I came back I found someone had visited. Now I have to wait on them to close their game and restart it so the servers will get updated.

Just a guess.