When you configure CRL checking, Horizon 7 constructs and reads a CRL to determine the revocation status of a user certificate.

If a certificate is revoked and smart card authentication is optional, the Enter your user name and password dialog box appears and the user must provide a password to authenticate. If smart card authentication is required, the user receives an error message and is not allowed to authenticate. The same events occur if Horizon 7 cannot read the CRL.