Parallels 11 activation on OS X 10.13.6 fails (Check your Internet connection)

Dear @Avinash Bundhoo, I'm experiencing the same problem as everyone else on this forum. Had to replace the motherboard on my Mac, and after trying to reinstall Parallels, I get the "can't connect to internet" error message when trying to activate the license key. Used to work just fine before. Tried all the recommended troubleshooting tips, but no luck I'm afraid. Are you able to help please? Many thanks, ed.

 

Having the exact same problem. Old laptop died, got a replacement and restored everything with Time Machine. Parallels 11 starts up fine but won't activate - keeps giving me the "check your internet connection" error even though internet is working fine.
I have my original license key and it's a paid license. Please send me those instructions, thanks.