Hello specialist?!
It is very simple, I have exactly the same issue, this is ridiculous !
I have used "Windows Device Recovery Tool " to reset my lumia 640XL" back to 8.1.
Followed the instructions, quite straightforward but for the exception than when the phone ask you to connect to you microsoft account I've got the following message (By clicking "Sign in") : "Can't connect , We can't connect at the moment. wait for a little while and try again".
Nothing to do with our wifi connection, nothing to do with any password etc... but everything to do with Microsoft again showing itself incompetent and we are quite frustrated now.
So my solution will be straighforward:
- FIRST - I am going to go on Android (oneplus3)
- SECOND - I am going to wait "a little while" days or perhaps 1 to 2 weeks max.
- THIRD - After that time, I am going to throw out the phone and for my personal satisfaction use a hammer to smash it.
Thanks Microsoft for your continuous incompetence on mobile phone and the money I have wasted when I bough that phone!