Exactly Same!!!!!
Windows 10 Pro (64bit) + Firefox 71 (64bit)

"Will not work on Windows 10 64bit. Does not recognize that the Add-On is installed, even though it is. As about 350 others have said, this is worthless. Keeps prompting me to download and install a file. Takes you into an endless loop of BS. I stopped trying. How is it possible that they have not fixed this issue. Not like Windows 10 and Firefox are new!" -Michael Lynch

Same!!!!!