Facebook v4a plugin frequently fails to connect to Facebook

Many thanks, great job!

It seems something else may have happened during the update of the v4a plugin. I keep getting this error now:

"Invalid appsecret_proof provided in the API argument"

The Baas provider that I am using is saying that they don’t support the $appsecret_proof and never have. But now, after the update of the v4a, it seems that this is somehow required. Please note that I have not touched any of the app settings in the facebook developer portal.

Has the update of the v4a changed what variables are required or used in the login process? What is an appsecret_proof?