I'm looking at this https://helpcenter.veeam.com/docs/backu ... ml?ver=120 documentation, and I found from the logs that I needed to install SQLSysClrTypes and ReportViewer before I can run the PowerShell script (below). However, that did not solve my issue because it now returns an error with code 1603; now I have tried installing MYSQL Express and PostgreSQL before running that command and still no luck. I know by default Veeam will automatically install PostgreSQL by default when installed through the menu, but it seems the documentation to install Veeam Backup And Replication Server is oudated.
I moved your post to the general VBR forum as it is not related to Powershell module and concerns VBR installation using CLI. Your command looks fine, you passed all the required arguments. Please check that all the components from software section here required for Backup server are installed before proceeding with unattended mode.
The EC2 instance running the script meets minimum system requirements. By default, Veeam v12 installs PostgreSQL if installed using clickops, but running the install in unattended mode does not automatically install PostgreSQL. I tried installing PostgreSQL first before running the script, but it still wasn't able to read the PostgreSQL config automatically.
Please note that installation in unattended mode will try to connect to a local Postgre server on 5432 port. If you use remote Postgre server or/and a different port, make sure to specify it in VBR_SQLSERVER_SERVER parameter in "(server):port" format. If your settings are default or custom and you already specified them, please contact our support to investigate the issue through logs.