I just renewed my subscription os antiVirus for Mac on my iMac. Installation went ok except validating installation key which has been trying over 24 hours (waiting validation server) to finish.
You can try to re-install the product after first having removed it with the Uninstallation Tool:
If that doesn't help or you don't want to try that, submit a Support Request and attach a file called FSDIAG. Instructions on how to generate that file:
Please try installation through the link below:
Before using the link, replace the XXXX-XXXX part with your license key, and then download the file.
Does this solve the issue?