I noticed that if a user isn't logged in and sends an item to cart the login pops up but the user isn't allowed to login. The login button does nothing. Hope to see it fixed soon.
Would you please give a video screencast regarding the issue in details to understand better for us ?
Here is the screencast: https://www.youtube.com/watch?v=qVu38hj6T4E
Ok, It actually totally controlled by Facebook. This popup for login is coming & controlled by Facebook. So we have actually nothing to do here.
In my guess it might be any issue of your browser, you can check by clear your browser cache or in other browser. Or it may any Facebook bug.
However we will check the matter in our end also.
Tried using multiple browsers but the same issue. Hope this can get resolved asap.