FB Login stuck on "Please, wait"

Hi there!

Whenever i try to login using Facebook, i get the popup window, enter my FB credentials, the popup closes and i then see the spinning wheel and “please, wait” message displayed on the single event page. However, nothing else happens after that, meaning it does not display the succesful registration message event though login has been successful (if i refresh the page i see the “You haven’t paid for this event” message).

Anything i should do to fix that?