I recently downloaded version 6.10.10. I love it and when we go over 10 computer we will be buying. I set it up and all was well, then I got a blue screen on my computer. When I got it back up my license key was gone. I asked for another one (this was before I realized I could resend the original key) and now no matter which I put in when I press Add the key disappears and nothing is added.
It did register originally but that was before the crash.