Cannot connect to DBA with "Unable to Connect to System Database" error (Win 10060 error)

If you see the following error message displayed when trying to connect to DBA (either at a workstation client or a standalone install):

This means either the Firebird Server service on the server (or standalone PC, if not using a client-server environment) is not running, or, more commonly, a software firewall or other internet security program is preventing communication to the database.

The most common is Windows Firewall, which comes as a standard component of the Windows operating system.

The simplest solution is to turn off or disable these software firewalls on each computer (including the server). However, if you must maintain them active, you will need to configure them (on clients AND the server) to allow the DBA program as an allowed exception or allow a specific port exception both inbound and outbound. The port that must be permitted is TCP port 3050.

The following link gives specific instructions on blocking or opening a port on a Windows Firewall for Windows 10, Windows 8, or Windows 7.  Please note, if you follow that linked guide, be sure to click "Allow this connection" as the action instead of "Block".  Also, we recommend only applying the rule to the "Domain" and "Private" network, not the "Public" network:

How to Block or Open a Port in Windows Firewall

The above recommendations should resolve 90% of the instances of this error.  If not, we've also seen success by following the recommendations within the article called "How to identify your server's IP address and use the IP address in the BDE settings".