I had this problem two days ago, when I was going to vacation with my sim family (CAS-created) in Riverview. It was their fourth vacation, (one in each vacationneighbourhood) and on their second vacation in "the desert". She that was booking the vacation had a mission in each vac-hood, so it could be due to having several missions.
When I arrived I've got the empty frame, but I tried to go to "change/edit town" at the vacation-NH and that worked
. I even could creata a family in CAS there. They showed up in the menu to.
I had a "clean game". No packages, only store-bought content. I couldn't do anything with moving sims in though, so I ended the game. I had patched and had HELS in. Soon after that I ended up with viruses/trojan in my PC so I have just re-booted my hole PC and is going to install again. Is hooping for better result this time...