On the new website, many of the header links for versions prior to the pydata theme transition point to 404 - not found.

To reproduce, navigate to Cantera.org and click on one of the items that have a version switcher (any except for community), and select any of the versions prior to. 3.1.0. The landing pages are

• https://cantera.org/3.0/sphinx/html/
• https://cantera.org/2.6/sphinx/html/
• etc.

In all cases, these are the 'reference' pages (YAML/CTI/Python/MATLAB). None of the other portions of the website (install/etc.) are accessible.

This issue was pointed out recently on the UG by someone trying to look up install instructions for 3.0.