Sorry my previos comment got submitted incomplete. What i was trying to say was whatsapp doesnt have to do with the location of the users as i use my whatsapp to talk to my cousin located all over the world that is some in india, usa, kenya, canada, singapore and australia. ANd you dont even need to put +1 for ur friends or ur numbe rif the +1 is not ur countyr code. Try to delete the app and reinstall it and request new access code. Also register ur correct contact number and tell ur friend to do the same. Hope this might solve ur problem.
You can also check this link it might help u out http://www.phonesappstabs.com/problems-with-my-whatsapp-messenger/