Have you self-hosted a WordPress site, gotten excited to use the WordPress mobile app only to then be greeted with this when setting up your site in the app?
Sorry, we can’t log you in. Unable to read the WordPress site at that URL.
So did I.
I read the FAQ and tested my XML-RPC service and it was working just fine as this was a fresh WordPress install, XML-RPC is enabled by default, and everything was pretty vanilla. Then I thought, “Perhaps I’m missing something on the server itself that’s causing this error.”
My php 7 installation was missing a critical package, php-xml. After SSHing in and doing
sudo apt-get install php-xml
sudo service apache2 restart
I was good to go.
Hope this helps.