I was using google authenticator. I tried with Authy and it worked. Why does it work with one and not the other?
Yes, it works fine for me too. I tried to set up a new account and that also went smooth. So, there will not be any problem in set up side as it works good for existing and new users. I guess QR code is not reading means he is not using the right app. Or uninstalling and reinstalling correct google authenticator/barcode scanner may solve this issue.