Hello @VikasRobert
The error is a sign your SSL cert for your authentication server expired and needs to be re-trusted. You will need to login to the ITA web client UI using a local user (a user which is not an AD/LDAP user account like the default "apc" user which is present by default). Once logged into ITA, go to the configuration menu, choose authentication servers, then edit the existing authentication server definition, scroll to the bottom of the edit window click OK and its likely you'll need to scroll back up in the edit window to see a pop-up which asks you to trust the authentication server. If you do, accept the trust, the login problem should be resolved.
Regards
Greg Sterling
