I have separate quicken files for my kids, and if I open those, they don't have this popup. I discovered that this problem is specific to a particular quicken data file that I use most often (with my data). If the Quicken file backs up when I am exiting, the popup pops up again on the way out, and I have to click it three more times. I have to click in the top right corner of the popup three times to make it go away.
I posted last week about a problem I've been having with Quicken 2017 and a popup screen that demands that I 'Enter Quicken ID Password,' but which contains no area for me to enter anything.