Last year I purchased the sketchbook pro subscription for windows 10. it costed $25 USD. I get that the program is "free" now, but I still want all the Pro features and im willing to pay another $25 for it. but HOW? There's a never-ending spinning circle of doom here.
You have an older version of Sketchbook. No need to buy it. Just login with your email.
See also: https://forums.autodesk.com/t5/sketchbook-forum/free-or-not-can-t-draw-anymore/td-p/8679148
David Lau