As somebody posted a solution below, I will merely repeat it: turn your mouse off and back on. It will then scroll. I had same issue and now it works.
Best regards
JeffT22
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution