I've renewed my TLS certificate but my website no longer works
Once your certificate has been renewed, you need to install the new certificate (.crt file) and the corresponding private key (.key file) on your web server. Contact your web hosting provider for assistance. If your website is hosted on our web hosting platform and you are using a third-party TLS certificate or a Gandi Pro/Business TLS certificate, install the new certificate and the corresponding private key on your instance.
Please note that for TLS certificate regeneration (for example, at the annual expiration of a TLS certificate purchased with a 2-year or longer subscription), the old version of the certificate is revoked within 48 hours.
Installing a manual SSL certificate on a Gandi web hosting