D6400 config screen not loading

[siliconglen]

Trying to log into D6400 to look at some possible connectivity issues (mobile won't connect on one wifi network)

I'm getting this far: 

Have powered off the router several times but can't get the config screen to load on either mobile or PC. Any suggestions?

[siliconglen]

If you can't see the image (I uploaded it, but just looks like a triangle) it shows me logged into the router but with no content visible except for the menu, top bar and a spinning icon.