Norton start-up stability

HI

I am using Norton Security 22.5.5.15 under W10. Regularly, I have connection issue. Lately I had a pop-up with "Invalid key" with a drop-down list, with a choice Enter New key. The day before it was working fine, and my subscription is valid until beg. 2017. Sometimes, Norton does not even starts, or does not connect automatically to my account, and I need to reenter my registration information. I am nearly asking myself if there is a virus preventing Norton to work correctly!

Does someone have the same problem?