Error 500 on dialog/oauth API after today's push at 8:21

Question

Our apps are getting error 500 on this call :

https://www.facebook.com/dialog/oauth?client_id=89dc1edc0036d868930ccbac657e8b7f&redirect_uri=https%3A%2F%2Fapps.fa

Answer 1

I can reproduce your problem by removing all cookies at facebook.com and then visit your posted link.

If you visit http://www.facebook.com once, then your URL will work. If found it now needs a cookie at facebook.com to work (named datr at facebook.com). There must be a change/problem at facebook.

It also works if you visit the corresponding login.php directly.