FF default settings must be changed
After trying this, it may be on the blame side of the new FF browsers, but I had to figure out why it would not work? I eventually figured out that FF has a default setting to disable javascript and pop-up windows which I changed in the settings! However after donating I still cannot get the better non-ad version to install! With that said, it's still a very good worthwhile add-on even with these problems! Thank you for your hard work!
Javascript is needed for conversion to launch, pls. raise a support ticket at http://yourvideofile.org/support.html using the contact support form with details of your donation.