LOL I do do the impossible, but I'm a good tester. I don't have any bad cc because this is a new game folder with all my old cc added back and I cleaned it all up before installing it. But, I did try something again. This time I sent my sim to another world (Midnight Hollow) and met the Doe family. When my sim got home, I chose the same house as before and did MC > Add Sim > Homeworld > Midnight Hollow > chose all the doe family (including a toddler and a pregnant sim) and they all showed up. So I have no idea why the other pregnant sim didn't show.

The buy/build screen was weird but hasn't happened since.

I just got another problem after travelling. I travelled to Riverview and met the Grisby family. Then I had my sim return home before the first day was over (only went to make Riverview show on the list of homeworlds). When she returned home, I picked an empty house, clicked onthe ground and chose MC > Add Sim > Homeworld > Riverview and selected all 3 members of the Grisby family. They all arrived at their new home in Cloverdale. When I checked their relationship panel it also showed each member was also in Riverview (foreign). Does that mean a copy of this family has been placed in Cloverdale or have I created another problem somehow?

Those kinds of "duplicates" usually resolve themselves eventually, often on the next save as, quit, and reload.

OK thanks igazor, I just shut the game down so I'll see tomorrow if it's resolved

Even then, don't panic or do anything drastic if the shadow "duplicates" are still there right on loadup (although this is where they usually disappear for me). The TravelDB file sometimes holds onto outdated information -- this is why some of us also occasionally get a barrage of notifications about sims in foreign worlds who are about to die of old age when we know that nothing of the kind is really happening.

But don't try to TA the apparent foreign dupes or invite them over or anything like that. The worst case scenario is that you may have to do a return round trip to Riverview and save/reload from there to get the unresolved "shadow" sims to evaporate by way of...I think it's Overwatch but ErrorTrap might play a role also.

Ok thanks igazor, I will check it out and see what's happening. I will not panic or do anything drastic LOL.

All my duplicates are gone

Oh no, I'm sorry what happened? How can we get them back? Oh wait...

(Just kidding, I figured this wasn't serious from the steps you described)

LOL, I wasn't panicking, just curious as to why they were showing in both places.