Version 5.2 to 7.1 all say they will work for FF 51.0 and later. When I tried 7.1 it did not work. I am using FF 56.0. The strange thing is that Mozilla addons thinks I am using FF 50.0 and gives me this warning:
This add-on requires a newer version of Firefox (at least version 51.0). You are using Firefox 50.0.
