To enable client PCs to display online update messages, proper server configuration is essential. You can set this up in two ways: by selecting either the port or program option within your control panel. Follow the method that best suits your needs.
Server/Main PC (Port)
Open Control Panel, Windows Defender firewall, advanced setting, yes.
Inbound rules, New Rules.
Select Port (rules that control connections for a TCP or UDP port), Next.
Select TCP and Specific Local Ports: 8903 (use this number), Next.
Select Allow the connection, Next.
Name: Access UBS Update Service (use this name), Finish.
Server/Main PC (Program)
Open the control panel, Windows Defender Firewall, advanced setting, yes.
Inbound rules, new rules.
Select program (rules that control connections for a program), Next.
Select this program path: %ProgramFiles(x86)\CommonFiles\SageSoftware\UpdateService\UBS.Common.OnlineUpdate.UpdateService.exe., Next.
Select Allow the connection, Next.
Select Domain, Private and Public, Next.
Name: Access UBS Update Service (use this name), Finish.