Can't start family.

When I try to start family sharing, I get error - cannot complete action. This action cannot be completed at this time.

When I press create an account for a child, it gives error - this person can not start or join family.

I have this problem since beginning of this year when I made a mistake and decided to try apple products.

I have purchased extra storage at iCloud. Also have bought some apps.

Still can't make a family sharing