Current FlashGot version (1.5.6.14) blocks new tabs to be opened after the first one on the latest Firefox release 53.0.2 (win32).
Disabling it solves the problem, but browsing without FlashGot is nonsense!
Does it happen to anyone else?
Mozilla/5.0 (Windows NT 10.0; rv:53.0) Gecko/20100101 Firefox/53.0