EXEXML Sensor returns PE231

EXEXML Sensor returns PE231. I am trying to use a custom powershell script to return useful information on DAG status. The script runs fine when manually executed but I get the aforementioned error. Any advice appreciated. have checked a similar thread but that fix didn't seem to work for me. Here's the script below:

#[CmdletBinding()]
#Param(
#  [Parameter()]
#   [switch]$Active,
	
#   [Parameter(Mandatory=$True)]
#   [string]$MBServer,
   
#   [Parameter(Mandatory=$True)]
#   [string]$MBDatabase   
#) 

$Active = $args[0]
$MBServer = $args[1]
$MBDatabase = $args[2]

Function LoadExchangeSnapin
{
    if (! (Get-PSSnapin Microsoft.Exchange.Management.PowerShell.E2010 -ErrorAction:SilentlyContinue) )
    {
        Add-PSSnapin Microsoft.Exchange.Management.PowerShell.E2010
    }
}

Function StatusValue($CopyStatus)
{
    If ($Active) {
            Switch ($CopyStatus) {
                "Mounted" {2}
                "Healthy" {1}
                default {0}
            }
    }
    Else { 
            Switch ($CopyStatus) {
                "Healthy" {2}
                "Mounted" {1}
                default {0}
            }
        }
}

LoadExchangeSnapin

Write-Host "<?xml version=`"1.0`" encoding=`"Windows-1252`" ?>"
Write-Host "<prtg>"

$Databases = Get-MailboxDatabaseCopyStatus -Server $MBServer
ForEach ($Database in $Databases)
{
	if ($MBDatabase -contains $Database.name) {
		$a = $Database.Status
		$b = $Database.CopyQueueLength
		$c = $Database.ReplayQueueLength
		$d = $Database.ContentIndexState
        
        $status = StatusValue($a)
        
		Write-Host "<result>"
		Write-Host "<channel>Status</channel>"
		Write-Host "<unit>Status</unit>"
		Write-Host "<mode>Absolute</mode>"
		Write-Host "<showChart>1</showChart>"
		Write-Host "<showTable>1</showTable>"
		Write-Host "<warning>0</warning>"
		Write-Host "<float>0</float>"
		Write-Host "<value>$status</value>"
        Write-Host "<LimitMinWarning>1</LimitMinWarning>"
		Write-Host "<LimitWarningMsg>Status not Expected</LimitWarningMsg>"
		Write-Host "<LimitMinError>0</LimitMinError>"
		Write-Host "<LimitErrorMsg>Status not Expected</LimitErrorMsg>"
		Write-Host "<LimitMode>1</LimitMode>"
		Write-Host "</result>"

		Write-Host "<result>"
		Write-Host "<channel>Copy Queue Length</channel>"
		Write-Host "<unit>#</unit>"
		Write-Host "<mode>Absolute</mode>"
		Write-Host "<showChart>1</showChart>"
		Write-Host "<showTable>1</showTable>"
		Write-Host "<warning>0</warning>"
		Write-Host "<float>1</float>"
		Write-Host "<value>$b</value>"
		Write-Host "</result>"

		Write-Host "<result>"
		Write-Host "<channel>Replay Queue Length</channel>"
		Write-Host "<unit>#</unit>"
		Write-Host "<mode>Absolute</mode>"
		Write-Host "<showChart>1</showChart>"
		Write-Host "<showTable>1</showTable>"
		Write-Host "<warning>0</warning>"
		Write-Host "<float>1</float>"
		Write-Host "<value>$c</value>"
		Write-Host "</result>"

		Write-Host "<result>"
		Write-Host "<channel>Content Index State</channel>"
		Write-Host "<unit>State</unit>"
		Write-Host "<mode>Absolute</mode>"
		Write-Host "<showChart>1</showChart>"
		Write-Host "<showTable>1</showTable>"
		Write-Host "<warning>0</warning>"
		Write-Host "<float>0</float>"
		if ($d -eq "Healthy") {
			Write-Host "<value>1</value>"
		} else {
			Write-Host "<value>0</value>"
		}
		Write-Host "<LimitMinError>0</LimitMinError>"
		Write-Host "<LimitErrorMsg>Content Index is Not Healthy</LimitErrorMsg>"
		Write-Host "<LimitMode>1</LimitMode>"
		Write-Host "</result>"
	}
}
Write-Host "</prtg>"