When I add the App ID and the App secret, which are correct, the secret is colored red. When I click to Save Changes, I get this error:
Facebook returned an unexpected error: An unknown error has occurred.
Try to resolve this issue, update the plugin or inform the author about the problem.
Your connection options could not be validated.
I have waited a while, and also tried resetting the secret to no avail.
Thanks in advance for your help, great plugin!