In general, when the system CA PAM certificate expires, it is still possible to connect to the Appliance, even though the majority of browsers will throw out messages warning about the connection and eventually also for some of them it won't be possible connect if a restrictive set of browser security settings is in place
However, there may be situations where an expired certificate will not allow under any circumstance to connect to the PAM appliance. No matter what change is made to the security settings of any of the browser, if the remote site is added to the trusted root or if address resolution is disabled, the message and the behaviour will always be the same: no access to any of the ssl-secured pages in PAM is possible. The error message obtained looks like the following picture
CA PRIVILEGED ACCESS MANAGEMENT, all editions
This situation may happen if the client is accessing CA PAM through a VPN. In this situation rules are more stringent and access won't be possible through the VPN until the certificate is updated in CA PAM
To correct this situation make sure to access the PAM instance through the internal network or locally and set the system certificate either to the self-signed certificate in PAM or to the renewed system certificate. That will reenable connections to CA PAM for clients connecting through the VPN.