The OneDrive sync client is an important Microsoft 365 component which underpins features like autosave and coauthoring of Office documents. During the March 15 Azure AD outage, the client had a meltdown and removed all the local copies of files stored in a SharePoint Online folder, seemingly because it couldn’t authenticate. The problem was easily fixed, but it’s a bad example of handling what could be a transient authentication issue.
OneDrive clients have access to version history for files stored in SharePoint Online and OneDrive (business and consumer). Until they don’t, which is why I am grumpy today. As it turns out, the feature works on one PC but not another, and that’s super-frustrating.