After changing the name of the server which hosts the SQL Instance for Netwrix Auditor databases you receive the following in Change Summary emails:
Error saving AD history to database: 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: SQL Network Interfaces, error: 26 – Error Locating Server/Instance Specified)
The server name is not correct in the product configuration anymore as well as in the SQL server configuration.
1) Open the Netwrix Auditor console
2) Navigate to Settings -> Reports
3) Click on Configure and change the SQL Server Instance name to match the new SQL Server name.
4) Verify the Report Server URLs are still accurate and change them also if necessary and then hit OK.
5) Modify the SQL Configuration by following the following technet article: http://msdn.microsoft.com/en-us/library/ms143799.aspx