The FogBugz database is down or could not be found.

Error: -2146232060: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

For security reasons, this cannot be fixed over the web.

Please edit the registry on the FogBugz server. The setting you want is HKEY_LOCAL_MACHINE\SOFTWARE\Fog Creek Software\FogBugz\C:/program files (x86)/FogBugz/website\sConnectionString.
Common connection strings can be found at connectionstrings.com. (Also please note that if your SQL machine is on a different server than your web server, you may have to use SQL Server Authentication, and not Integrated Authentication.)

To use SQL Server, set this to Server=server;Initial Catalog=database;MultipleActiveResultSets=true;Integrated Security=SSPI; for Integrated Authentication
or Server=server;Initial Catalog=database;MultipleActiveResultSets=true;User Id=sqlserveruser;Password=sqlserverpassword; for SQL Server Authentication

To use Access, set this to Provider=Microsoft.Jet.OLEDB.4.0;Data Source=filename