A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
This started a few days ago for me. I found that if I copy the files over to C: drive and access them from there they work OK. I'll just back them up to OneDrive every day if I remember. Looking at some posts it seems this problem has been around for some time, but MS has remained quiet on the matter. Disappointing when I'm paying my subscription to OneDrive/Office 365