The oauth dialog page at facebook.com is generating a 500 error. We have a few web applications that use the Graph API, and all of them are experiencing this same error.
The full URL is: https://www.facebook.com/dialog/oauth?client_id=[app_id]&scope=publish_actions&display=page&redirect_uri=https%3A%2F%2Fwww.mydomain.com%2Fcallback%2F&state=[unique_number].
We created a new test application, and exactly the same happens there as well. We use the latest Facebook PHP SDK. We do not use JavaScript in this process. We've tried different scope parameters, and that made no difference.
This process worked up until some time late on March 27 2013 or early on March 28, 2013. Then it started kicking back the 500 error.
