I drag a piece of furniture to the family inventory via buy mode and the circle with the red slash comes up, which means I can't put it in there. I try and try again and it just won't work. I tried taking some things out of the inventory (I didn't put them in, were already there) because I figured it was some spacing issue, but it doesn't work. I have some sim families where it does work however, I can put things in even if they already have a ton of furniture in their inventory. So I know I'm not doing anything wrong from my side. But with other families, even when they don't have much, it doesn't work. I can't put furniture in the personal sim inventory either.