PowerShell script to configure SQL Server 2017 Reporting Services

Configure-Sql2017RS.ps1

<#
#>
function Get-ConfigSet()
{
	return Get-WmiObject –namespace "root\Microsoft\SqlServer\ReportServer\RS_SSRS\v14\Admin" `
		-class MSReportServer_ConfigurationSetting -ComputerName localhost
}

# Allow importing of sqlps module
Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Force

# Retrieve the current configuration
$configset = Get-ConfigSet

$configset

If (! $configset.IsInitialized)
{
	# Get the ReportServer and ReportServerTempDB creation script
	[string]$dbscript = $configset.GenerateDatabaseCreationScript("ReportServer", 1033, $false).Script

	# Import the SQL Server PowerShell module
	Import-Module sqlps -DisableNameChecking | Out-Null

	# Establish a connection to the database server (localhost)
	$conn = New-Object Microsoft.SqlServer.Management.Common.ServerConnection -ArgumentList $env:ComputerName
	$conn.ApplicationName = "SSRS Configuration Script"
	$conn.StatementTimeout = 0
	$conn.Connect()
	$smo = New-Object Microsoft.SqlServer.Management.Smo.Server -ArgumentList $conn

	# Create the ReportServer and ReportServerTempDB databases
	$db = $smo.Databases["master"]
	$db.ExecuteNonQuery($dbscript)

	# Set permissions for the databases
	$dbscript = $configset.GenerateDatabaseRightsScript($configset.WindowsServiceIdentityConfigured, "ReportServer", $false, $true).Script
	$db.ExecuteNonQuery($dbscript)

	# Set the database connection info
	$configset.SetDatabaseConnection("(local)", "ReportServer", 2, "", "")

	$configset.SetVirtualDirectory("ReportServerWebService", "ReportServer", 1033)
	$configset.ReserveURL("ReportServerWebService", "http://+:80", 1033)

	# For SSRS 2016-2017 only, older versions have a different name
	$configset.SetVirtualDirectory("ReportServerWebApp", "Reports", 1033)
	$configset.ReserveURL("ReportServerWebApp", "http://+:80", 1033)

	$configset.InitializeReportServer($configset.InstallationID)

	# Re-start services?
	$configset.SetServiceState($false, $false, $false)
	Restart-Service $configset.ServiceName
	$configset.SetServiceState($true, $true, $true)

	# Update the current configuration
	$configset = Get-ConfigSet

	# Output to screen
	$configset.IsReportManagerEnabled
	$configset.IsInitialized
	$configset.IsWebServiceEnabled
	$configset.IsWindowsServiceEnabled
	$configset.ListReportServersInDatabase()
	$configset.ListReservedUrls();

	$inst = Get-WmiObject –namespace "root\Microsoft\SqlServer\ReportServer\RS_SSRS\v14" `
		-class MSReportServer_Instance -ComputerName localhost

	$inst.GetReportServerUrls()
}

Apologies for my stupidity on this. I am attempting to use this script to configure SSRS 2019 as part of a wider VM build process.

When the script is run, it creates the $dbscript script, but fails on "You cannot call a method on a null-valued expression" somewhere inside the generated SQL script (over 17,000 lines long)...

Any ideas where I might start looking?

Thanks!