Correct Format? (Family Plan Invites)

[TFLyons5]

I signed up for Family Plan and am trying to invite my sister (Yes. We reside in the same household).  When I put in her Email Address, correctly, it still says put in "correct format".  Any ideas?  

[big_dgent1991]

I'm having the same problem.. I had a family plan before but cancelled with a new addition to the family. Now that I'm trying to get it up and running again, it's telling me to enter the email address in the correct format.