QuickBooks 2015 is a great version. But it’s quickly going away.
Every May, Intuit retires their oldest supported version, to keep their three version support window in sync. So QuickBooks 2015 (all desktop editions) will have “service discontinued” (AKA “sunsetted”) after May 31, 2018.
I thought version 2015 was an unusually stable version, from the point of view of one who sees a lot of QuickBooks data problems.
Note: If you are not using any add-on services to QuickBooks 2015, you will still be able to use the QuickBooks 2015 software. But there will no longer be live support available for it through Intuit.
Hasta la vista, QuickBooks 2015!