glossary pages returning 404s

I just installed the Yoast SEO plugin this morning, not sure if that’s related. Saw this coming up in the 404 monitors so I hit it and it’s in fact not loading.

glossary page
http://www.whitelotusclinic.ca/glossary/
glossary term
http://www.whitelotusclinic.ca/glossary/tsh/

Seen this before or any idea what might be causing this? Ever used the Yoast SEO plugin? No idea if there’s a relationship but unfortunately it’s too awesome to remove and I’ve already used it to update the metadata for significant chunks of the site.

Anything I can do to identify the problem? New to wordpress but not development. Want glossary back, it was nice! 🙂

http://wordpress.org/extend/plugins/wp-glossary/