airport express will no connect to airport extreme
I have tried to get my airPort Express to connect to AirPort extreme via my iphone using the setting app. It finds the express and it knows i have the extreme. I tell it i want to extend my current network and it finds both units but i get and error message " an unexpected error occurred" try again, ihave tried several time but to no avail.
iPhone 6s, iOS 9.2.1