Kalyr

A bit of searching in the codex and I figured out how to do it, with one line in the customised tag templage immediately before get_template_part

query_posts( $query_string . '&order=ASC' );

Panic over. I had a bunch of redirects in my .htaccess file I’d completely forgotten about, which redirected old URLs from my old Moveable Type installation. Nuking them makes the plugin work fine.

Website is https://www.kalyr.com