I've bought recently a copy of Parallels for Mac 10. Now I've got a subscription to 11, but the server is rejecting my license as I have not registered the license for 10 on my account, so looks like I cannot use the product I've bought. What to do? I've tried to register my Parallels for Mac 10 license to my account, but I could not. What can I do to use my Parallels for Mac 11?