A Microsoft file hosting and synchronization service.
I just saw a post on another site which states the problem is due to the version of OneDrive. It all started with a recent update. This seems to be true as I have 2 computers running build 25.041.0303.002 which are not working and 2 running OneDrive build 25.035.0223.003 which work fine. Now if I could only get instructions on how to roll back OneDrive to the older version!