I installed "Download Helper" and I can't get it to work. When I first installed it & paid for the license, it worked twice... then it would no longer see any video's playing on YouTube... and there aren't any download links under the video on YouTube. The three little balls i the upper right corner do now rotate or move either... is says there is no content... Macbook Pro OSX El Capitan version 10.11.6 Any help is appreciated...