FAQ content

Why is my browser displaying a warning page when viewing my site over HTTPS?

In this article

If you attempt to visit a site over HTTPS, your browser will prevent you from proceeding if there are issues with the site's certificate.

Example of a security warning in Chrome


Did you update your CNAME records to use our secure endpoints?

If you did not update your internal and external CNAME records to point to our secure endpoints, your site will be unable to load over HTTPS. This will commonly result in a warning message like:

This server could not prove that it is [your site's URL]; its security certificate is from *.libguides.com. This may be caused by a misconfiguration or an attacker intercepting your connection.

To fix this, please ask your IT staff to update your CNAME records. If they did update the CNAME records already, confirm that they are set for the correct region and there are no typos.


Domain name in certificate doesn't match the site

View your certificate to confirm that the domain name in the Issued To field matches the domain name for your site. If it's a wildcard certificate, it should look something like: *.yourdomain.edu


SEC_ERROR_UNKNOWN_ISSUER error

According to Mozilla Support, this can be caused by the following:

  • Missing intermediate certificate
  • You're using a self-signed certificate, rather than one from a recognized certificate authority

There are a several free tools that can help you identify specific issues with your certificates. Please see the links at the end of this article for examples.