Avast Report License Invalid

I have over a year on my Avast subscription and am getting a License invalid message.Can someone please help.
Thanks

Check your system date, day/month/year and adjust as required.

System Date/Time/Year are correct. Still get message.

What were you doing when you got the error ?

What version of avast do you have Home or Pro ?

Avast home and was doing nothing it just keeps popping upon the screen every so often.

When or did you enter your registration key ?

Q: “Invalid license number”. Why? http://www.avast.com/eng/faq-invalid-license-number.html Or Insert Registration Key - Video

Check the about avast (right click the avast ‘a’ icon), Updates Expiration date and report what it says.