December 2012 Migration Not Available in App Dashboard
I think the issue could be related to the oAuth changes that are in staging for the Announcing December 2012 Breaking Changes (90-Day Notice). I would like to DISABLE this migration, but I don't see it in my Facebook App Dashboard.
Anyone have any ideas?
The ability to enable/disable December 2012 Breaking Changes in the app settings will be available in a few days after it has been announced.
Thus, the breaking changes aren't in effect yet, which means your error is not related to the December 2012 Breaking Changes.