For installing a failover server for the Endpoint Protection Manager, below are the requirements.
Installing a second site for failover and load balancing fails when using the embedded database.
1) Use a Microsoft SQL Server database to enable the failover and load balancing feature. If you plan to set up additional management servers for replication you must use a SQL Server database for the management server. The embedded database does not support the load-balancing configuration.
2) Install Visual C++ 2017 Redistributable
File Name: Vc_redist.x64.exe
3) Install ODBC Driver (17.x) for SQL Server
File Name: msodbcsql.exe
*Please note that at the time of writing this is version 220.127.116.11 which covers CVE-2023-29356.
4) Install Microsoft Command Line Utility (15.x) for SQL server.
File Name: MsSqlCmdLnUtils.exe
5) Download and Install SQL Native Client
File Name: sqlncli.exe
6) Install the SEPM as a load-balancing server
Note: When adding a SEPM for failover and load balancing, it must be installed using the same version installed on the first server. Installing a different version may appear to work, but the SEPM service will fail to start on the new SEPM.
Please note : ODBC driver 18.x is NOT supported by Microsoft with SQL command line 15.x - https://github.com/MicrosoftDocs/sql-docs/issues/9188
As of this writing Microsoft only supports ODBC 17.x with the 15.x SQL command line tools