Legacy Connect Auth stopped working

Question

I'm working with an application that was built and integrated to Facebook using the legacy connect auth:

https://www.facebook.com/login.php?api_key={appkeyhere}

Starting sometime the week of Oct 22, 2012, existing users who login to the app using the above URL get redirected to https://www.facebook.com/login.php?login_attempt=1 and have a blank white screen. New users signing up to the app for the first time get redirected back to the application site.

I had the people who maintain the site check the deploy logs to see if there were breaking changes deployed to the pages that service the back end OAuth and they haven't made any changes.

Any ideas on where to start to try to debug this issue?

Answer 1

Only the current documented authentication flows in the Login documentation are supported - last week the last of the legacy endpoints (most of which were deprecated in October 2011) were removed - For desktop apps there's more specific documentation at https://developers.facebook.com/docs/howtos/login/login-for-desktop/ which covers the details