When trying to connecting remotely via File > Open > Remote Project, the Available tab will only show 4D Servers on the default port 19813. If 4D Server is not showing up on the Available tab, it could be due to one of the following:

1. The server is not running.
2. The server is running on a different port other than 19813
3. The server is running from a different subnet.

When in doubt, one way to know for sure a server is running is to connect via the Custom tab and enter the IP address and port directly.