Not definite that it was related, but the problem cropped up after the first attempted site update using a new Mac Book Pro that I'm just setting up to be my new primary computer. There could be other issues as I work to get the new one configured to do everything I need it to do.
On the up side, the actual site update data processing part took less than half as long as on the old computer, and our site's maps look spectacular on the bigger retina display!
