The error was caused by having the following string in the URL:
-–-
as in this url:
http://www.cyclingutah.com/category/sport-and-touring/road-–-sport-and-touring/page/2/
I'm not sure how the three dashes got in there before, but it cause issues with Wordpress SEO. It doesn't cause issues if WP SEO is deactivated.
Hence, WP SEO is not handling the URL properly.