My sims keeps disappear

[grannvirve]

So, I've had this problem for a while now, and I seriously hate it!

I'll try to explain; Let's say I have a family in a big house I made.

I want the daughter to get married, so I log out of that family to make a husband for her in another family.

I place him out on an empty lot, builds him a house and exits the family.

When I come back the entire family is gone, their sisters brothers and house!

The same things happen to my other families besides the one I just made.

All of my other families, like they never even existed!

(Yes I use mods)

Help!

[Phantomlover1717]

Are you using the same save file to move the new husband in?