I just put in the powerline adapter and connected two machines. It all works. If I go to the web interface I can login using the default password, admin. If I open the tpPLC utility I see the network of devices, but if I try to see the system settings for any device I'm asked for a userid and password. I've entered the defaults (admin/admin) but that fails. I've tried various combinations of the SSID, 'admin' and the WIFi password, but nothing works. I used the web interface to change the password to 'admin' and that succeeds, but I still can't do anything using the app.