Unable to add family members to family sharing

I am trying to get family sharing set up mostly in order to use Apple Music. I have set up a family account, and my user is the organizer. I am unable to add any of my family members. Each time I try to add one, it results a blank alert window that says "Go Back". I'm sure I'm using the correct emails. I can't seem to attach a screenshot to this post. I don't currently have an iOS device to try this on, I only have my Mac. I'm wondering how to proceed.