Pop up box Norton 360 requesting password?

I've used Norton 360 for years, and always found it reliable. Did a full system scan yesterday, nothing found except some cookies.

After the scan I started getting a Norton pop up box, constantly asking for my password? The box has the email [Removed] (Not mine and grayed out)) below this is a box asking for my password. I closed the box with task manager, there is no x in corner to close it. A few minutes later it popped up again, asking me to enter my password?

Any ideas please? 

[Edit: Removed email address to conform with Participation Guidelines & Terms of Service ]