Just installing an antivirus program doesn’t complete your job, you also need to activate the software to access its protection and services. But at times the user is not able to do it because of some error code or error message. This mostly happens when the user tries to re-install the program on another device.
While activating the program the user might get an invalid key error. There can be different reasons for this error. The first thing you should check is that you have entered a correct product key. Also, check that language and country is correctly filled as that might also cause the issue.