When attempting to index a page via the diagnose tool in the Domains section, it returns back an error:
Our crawler only visits and crawls webpages that have a valid SSL certificate. This error is returned when the site’s SSL certificate is expired or is from an untrusted authority. To resolve,
Contact your website administrator to update the certificate
Once the certificate is valid and updated, try diagnosing a link via the Diagnose tool.
If you confirm that the certificate is valid but you still receive this error, then contact us via Help Desk.