Possible Scam about Norton Safe Web Extension

This morning on my MacBook Air I received this message Norton Safe Web Extension for Safari is ready to install. I have this extension installed already.So this a scam?

It is a legitimate Norton message. Unfortunately there seems to be something wrong with the implementation of the message box. It should have a do not ask again link that works, but some report it does not take effect properly. 

Norton is aware of this issue and is working on a fix.

 

I have had the same notice twice already.  I already have the Norton Safe Web Extension installed also.  I wonder if its a glitch or error.  I ran MalwareBytes and Trend Micro House Call - all clear.  I also ran a full Norton scan and all clear.  Any assistance a Norton expert can offer or an IT expert can offer would be helpful. Thanks.

I and many in my company have been having the same issue. As the IT director, I told everyone it was an update but now I am wondering and beginning to worry.