New Extender setup fail

Hi there, 

I have set up the AC1200 within my house.  I can connect to it via my printer and Iphone however when i access internet - the "Set new extender" box pops up.

It asks for email, password and two security questions however after i completed the fields, it takes me nowhere.  Simply empties the boxes to start again.  I cannot acces the internet from it. 

Your help is appreciated. 

KP