I have Microsoft Office 2016/365 installed as a Microsoft 10 App (aka. My Office or Store version). I have a paid active Microsoft office 365 subscription, but the NumXL installer can not detect my Excel installation, and refuses to continue.
How do I know I have store version?
In Excel, go to the "File" tab, then select "Account" (bottom), and examine "About Excel". If you see "Microsoft Store" or "Click-to-Run". in the description, then you have the store app version (see example below).