Hi,
It works, you save me, Thank you very much!
Oh, what did you do that worked for you? Why are the instructions not presented here?
I am having the same problem, I believe.
I have an old Mac Pro running El Capitan, which is the latest it can run. I use this as an FTP server, for video editing, and for running some Parallels virtual machines. Recently the machine died, and I bought a replacement machine identical to the first.
I moved all my hard disks over and the new machine successfully fired up. A perfect replacement for the dead Mac Pro except for one thing. Parallels Desktop 11 refuses to recognize my registration key. That's interesting. Is the registration tied to the processor and/or motherboard of the old dead Mac?
So, even if I type in the registration key, it responds with "Unable to perform the operation. Please check the internet connection and try again."
There is nothing wrong with my internet connection.
So, what is the answer? Will a copy of Parallels Desktop 14 (the last version that runs on El Capitan, I think) work? Or will I also be unable to activate that version?
Please help,
Thanks,
-Carl