My Sims disappeared when I came home from Trip

[ekunsworth@gmail.com]

One of my two sims traveled to China. When she returned, she wasn't there, neither was the other sim. I mean, there were no face icons, I can't access their motives, info, work, etc. I can't see them or direct them to do anything. When I hove over their house, I get "ring bell" but that isn't dimmed, i.e. I can't ring the bell (not that I want to).