Network problems
A FileMaker Pro client can't find FileMaker Server databases on the network
Verify that TCP/IP networking software is properly configured on the host and client computers. Verify that the simultaneous client limit you specified has not been reached.
FileMaker Pro databases shared via TCP/IP can be opened remotely using the list of local hosts, the IP address of the host machine, or the DNS name of the host machine if one has been defined. For example, a database hosted from a computer with an IP address of 192.168.10.0, and a DNS name of host.domain.com can be opened by entering either the IP address or the DNS name in the Network Path dialog box, using the format fmnet:/192.168.10.0/<filename>. (Note that fmnet:/ uses a single slash.)
Note FileMaker Pro also supports IPv6 addresses in the form of eight four-digit number groups, separated by colons and surrounded by square brackets ([]). For example, fmnet:/[2001:0DB8:85A3:08D3:1319:8A2E:0370:7334]/<filename>
If no FileMaker Pro client computers can see FileMaker Server in the Hosts dialog box, check the server network connection, and make sure the FileMaker Server ports are open on any firewall.
Clients cannot access the FileMaker WebDirect Launch Center
Verify that the clients are specifying the correct IP address or domain name for the machine running the web server component. For a multiple-machine deployment (FileMaker Server only), have clients try using the IP address or domain name of a FileMaker WebDirect secondary machine.
If you import a custom SSL certificate, clients must use the fully qualified domain name instead of the IP address.
If you make changes to the network configuration, the domain name, or the SSL certificate on a secondary machine, you must reinstall FileMaker Server on the primary machine, then remove and reconnect the secondary machine (FileMaker Server only).