Really Microsoft? Something went wrong.  I suppose it would be way too much trouble to say WHAT went wrong, or give any other diagnostic information at all.  Talk about inane!

So I went to the Service status link, and it shows OneDrive up and running.  OK, but not in MY case.  So I try another login I have and it works fine.  Apparently only the documents and files I have under THIS account are (I hope temporarily) unavailable.  Good job I didn’t have business critical data in there.