Firefox, VB Cloud & Facebook Connect problem.

[Dapol_andy]

I've discovered an issue with Facebook connect and Firefox (V. 47). Very simply, the button isn't showing up in the login dialogue. If a user attempts to sign-up using FB, then the page refreshes.
This function works flawlessly with current versions of IE, Edge, Chrome and Safari

It seems very similar to this issue: http://tracker.vbulletin.com/browse/VBV-9378
Any Suggestions?

[Dapol_andy]

FYI: This seems to have started with Firefox R42.0 onwards (inc 48.0b1) Versions older than this work OK.