An invitation doesn't work

• Expired — invitation links are valid for 7 days.

• Already used — each link works once.

• Wrong account — the link only works for the invited email address. Sign out and sign in (or sign up) with that address.

• Email never arrived — check the spam folder. If invitation email isn't set up, the admin shares the link directly instead.

An admin opens the pending invitation and chooses New invitation link, then shares the new link. The old one stops working.