Get-QADComputer_Array error

Hi Team,

I am new to the quest powershell and I am using Quest One ActiveRoles Management Shell for Active Directory for querying the active directory.  When i try to query whether a server is present in AD or not it throws an error message: Get-QADComputer : Index was outside the bounds of the array.

Here is my code. please help me in finding out where i am going wrong.

param(
[Parameter(Mandatory=$true)]
[string]$hostnames,
[Parameter(Mandatory=$true)]
[string]$AD_SA_id,
[Parameter(Mandatory=$true)]
$ADpswd
)

$Password = ConvertTo-SecureString -String $ADpswd -AsPlainText -Force
$Cred = New-Object System.Management.Automation.PsCredential("$AD_SA_id",$password)
 
$test = Get-QADComputer -Identity $hostnames -Credential $Cred
if($test -ne $null)
{
"$hostnames found in AD"
}
else
{
"$hostnames not found in AD"
}

Thanks in advance!