http://extempore.pjk-survey.com/tags/ does not display any tags.
My blogs are all public (that is, not private) so that should not be a problem. However, the next cause offered on this forum has been wp_site_posts table.
I checked my database, and cannot find a wp_site_posts table at all. So I guess that is the problem.
Does Global Site Tags required some other plugin to work?