The error message "Failed Connecting to Server" appears in the NES Setup wizard on the Database page after you configure the connection string for a remote SQL server, and then click Test.
Additionally, when you click Verify Users, the results also display an error. The following figure shows this error message.
This error message appears when port 1433 is not open between the remote SQL server and the NES server.
Open port 1433 bidirectionally between the NES and SQL servers.