This issue happened to me because I accidentally sent one of them on tour, or the mom had her baby at that time, I can't fully remember. The parents never left for vacation but there pictures became greyed out. The parents were playable like normal but you are unable to click on them from the relationships tab. This is annoying because I had my teen>turned young adult move out and they would like to call home every once and awhile, but they are greyed out. Is there any other way to fix this other than starting the family in a new game? I have never used mods, and if that will work I am interested in more details.
Thanks a Ton!!