I use my current license for a newer version on my main Mac, but I also have a license for Parallels 10 I'd like to run on my backup Mac running an older OS. When I try to validate the copy, it says my license has been 'blacklisted'. What up? Can't get a phone number to call in or an email address to contact support. I don't FaceBook or Twitter. I am a tech support that installs Parallels for many of my clients, never seen this before.