Ideas
IDK if this has been suggested, will help anybody, or is even allowed, but this is still happening and was making my game unplayable. I downloaded Top Rapidity's Don't Take Away My Child mod on MTS. It completely disables the Social worker call and I was able to resume my legacy. I figure this is a good a fix as any until EA gets around to fixing the issue.
I actually used this but it didnt do anything for me. It just let my Sim plop into oblivion.
I even tried finding the Sim in the Manage World Overview but the Sim was simply lost.
Its still happening and I get Pop-Ups every Morning that someone was adopted by another family(without someone dying in said family, which normaly causes adoption). It also happens to Pets of any kind.
Its so annoying.