I have upgraded to latest version of Mozilla but am getting the "video unavailable. this video is restricted" error message when trying to play some but not all You Tube videos. I have to copy and paste them in Safari in order to play them. THis is for an individual, private person, not a company so there is no administrator. Other posts have had this same problem but no one has provided an effective resolution or clear explanation as to why this is happening and how to resolve. I assume this is a Firefox issue since there is no problem playing the videos on another browser. Suggestions please