The client system is unable to download the PAC File from the PAC File Management System and connect to the Web Security Service.
Network environment or firewall is blocking access to the IP addresses where the PAC File is hosted on PAC File Management System.
If your firewall does not allow white-listing "pfms.wss.symantec.com" by DNS, allow the following static IP address: 34.120.17.44 (November 7, 2020).