i am using Chrome - and my browser was not logged into my google account (gmail) - after clicking the sing-in link i just had a blank page
i noticed in my upper right coroner of my browser that i was not logged into gmail for the browser so i did that and knolly just logged in...
for the "less technical" this might have been more frustrating than it needed to be - instead of a blank page maybe a request to auth with google could be displayed? (assuming that is what the issue was)