Smart wizard won't open

I cannot get either of a pair of WN3000RP to connect to DG834N. I am unable to get the Smart Wizard to open on wireless pc or ipad to make the connection. Link rate and status lights only are green. "unable to find mywifiext.net". I have hard reset numerous times. These extenders are very temperamental. I doubt that this is a new problem for most users but someone could point me in the right direction. It would save me chucking these things in the bin! Thanks in advance to anyone who can preserve my sanity!