I saw this same issue on the actual Norton forum website and there has been no responses...I experienced the same issue twice...I have had a pop up indicating Norton Safe Web Extension for Safari is ready to install. I have this extension installed already. Would this be a possible scam. Thus far no expert from Norton has responded and I can't seem to find any other forum addressing this.
Solved! Go to Solution.
Could you please delete the extensions from Norton and then reinstall them using the steps here https://support.norton.com/sp/en/in/home/current/solutions/v58055475_EndUserProfile_en_us This should fix the issue. Let me know what happens.