[tzs]

I suppose this explains why OneDrive is down.

Attempting to save to my OneDrive folder on my Mac gets an error in Excel, and suggests that I save a copy to somewhere else.

Attempting to view my OneDrive files via the web interface shows no files and then eventually says something went wrong. Retrying cycles among different errors includes GeneralError, ServerTooBusy, and telling me to make sure I don't have any firewall or plugins that could be blocking access to api.onedrive.com.