Then perhaps force close all your apps, turn your phone off and on, or reset your router/modem. It could be that your game is currently running on a very high memory and needs to be reinstalled. Do you visit neighbours every day? or is your kingdom heavily loaded with items and deco? Sometimes storing walls and roads and unnecessary items once you've reinstalled (before you visit anyone else and increase your cache) can fix the problem.
(snap Elsa! )