delete .. mysterious hopkinton thing fixed .. who knows whether caused by CCC or what

I don't think it's a good idea to delete a post about an issue. If other people experienced the same problem and it's intermittent, perhaps they could help document it. Or if it's user error, people would know how to avoid it.

This was, I believe, a very special case, and when I first posted had forgotten that there were two factors, not just one:  installed Hopkinton and also in the same period of time experimented with using a Zoom H4N recorder as temporary audio interface.   Together, they didn't work too well. 

Okay, thanks! IIRC the issue / problem is that Zoom never released 64-bit Windows ASIO drivers for the H4n, but did for the H5. So this probably was worth mentioning, as this reply should show up in a search for "H4n 64-bit windows problem."