Null-valued expression for script on WSUS? - windows

Question

I am trying to retrieve a list of updates in the scope. My code is as follows:
#Loads Microsoft.UpdateServices.Administration assembly in order to connect to the WSUS server
[reflection.assembly]::LoadWithPartialName(“Microsoft.UpdateServices.Administration”) | Out-Null
#Make the initial WSUS connection by using the .NET accelerator [Microsoft.UpdateServices.Administration.AdminProxy] and the static method getUpdateServer(), which requires two values: the WSUS server name and a Boolean value for a secure connection.
$wsus = [Microsoft.UpdateServices.Administration.AdminProxy]::getUpdateServer()
#Creating the Computer Target Scope object
$computerscope = New-Object Microsoft.UpdateServices.Administration.ComputerTargetScope
#Find all clients using the computer target scope
$wsus.GetComputerTargets($computerscope)
#Gets computer status
$Wsus.GetComputerStatus($computerscope,[Microsoft.UpdateServices.Administration.UpdateSources]::All)
When I try to run the following:
#Provides a summary of whether the clients that are specified in the scope require the update
ForEach($update in $computerscope)
{
$update = $wsus.SearchUpdates($computerscope)
}
$update[0].GetSummary($computerscope)
I receive the following error:
You cannot call a method on a null-valued expression.
At line:6 char:1
+ $update[0].GetSummary($computerscope)
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (:) [], RuntimeException
+ FullyQualifiedErrorId : InvokeMethodOnNull
even though I am passing $computerscope in the GetSummary method.
Any guidance would be appreciated.