Can't add sims to dynasty

Hi! Just purchased and installed Sims 4 Dynasty expansion.

I created a new Dynasty, including the skills and ideals without any problem. However, I cannot add anyone to the Dynasty. When I click "Add Members," the box that should have options to add is completely blank. My Sim lives with 1 other person, who she's engaged to. I cannot see that Sim nor any others at all. Screenshot attached.

I quit and tried again (error still happened), and I repaired the game as well (to no avail). I don't have or use any mods. I'm playing on a Mac laptop.

Please assist! Thanks.