Comment 1 for bug 1353951

I'm having the same problem here. It starte started a few weeks ago (i.e. it worked at the beginning).
I'm seeing this on two machines running 14.4 LTS 64bit.

Steps to reproduce:
1) open gnome-online-accounts
2) click + and add a google account
3) enter user name and password
4) confirm permissions for gnome
5) Black window pops up and asks for google password, but does not accept the correct password.
    Google Contacts are not available in Gnome or Thunderbird