Just installed this extension on FF v56.0.2 and it does absolutely nothing when I click the button. I restarted FF and still nothing! Is this extension incompatible with some other extensions? Which ones? If anyone can offer a solution - I'll try again. Otherwise guess I'll move on.

Update: I uninstalled and reinstalled as requested. Version is 2.1.0. Now get "Ack! Invalid URL' when I try using this extension. Maybe not ready for "prime time"?