An error has occurred while establishing a connection to the server

Valid for Sitecore 5.3

This error generally indicates an error in the SQL server database configuration.

Ensure installation and configuration options for SQL Server have been followed
- For instances of SQL Server 2005 running on the same host, the serverMode attribute of /configuration/sitecore/connections element in web.config can be set to File and the serverName attribute of the /configuration element of /App_Config/SqlServer/FileConnections.config should reference the SQL Server/instance such as .\SQLEXPRESS, HOSTNAME or HOSTNAME\INSTANCENAME
- For remote SQL Server instances, the serverMode attribute of /configuration/sitecore/connections element in web.config can be set to Server and the serverName attribute of the /configuration element of /App_Config/SqlServer/ServerConnections.config should reference the SQL Server instance such as HOSTNAME or HOSTNAME\INSTANCENAME
Ensure firewalls do not restrict access from the web server to the database server by accessing the databases on the web server through another tool such as SQL Server Mangement Studio