Windows 10 version 1909. I have been using the desktop app of OneNote 2010 with no issues until suddenly last week when logging in - using MS account credentials as always before - all pages are no longer visible and "There are no sections open in this notebook or section group" appears. When I login to onenote.com, the entire notebook is there but the pages load slowly and the whole web-based use of OneNote is sluggish and not what I want to use. When I'm logged in to the desktop app, I can manually have it sync but still nothing loads.

Thank you in advance for suggestions to get this resolved.