PowerShell script doesn't work correctly from Windows Task Scheduler

Question

Overview: I have a script I am using to query new application requests within SCCM via WMI. The script works perfectly when launched manually within a PowerShell console (either elevated or not, doesn't matter). I need to run the script through Task Scheduler. Currently set up to run with admin credentials and the checkbox for 'Run with highest privileges' is checked.

The Issue: Won't run correctly from Task Scheduler within Windows Server 2008 R2. No errors are reported (task scheduler returns error code of 0) but it doesn't seem to proceed past the line that reads:

$GetAppRequest = Get-WmiObject -Class SMS_UserApplicationRequest -Namespace root/SMS/site_$SiteCode | Where-Object {$_.CurrentState -like "1"} | ForEach-Object {

Here is the full script:

#Hard-coded variables
$SiteCode = "MySiteCode"
$ComputerName = "My-SCCM-Server"
$GUIDFilePath = "C:\Scripts\SCCM\GUIDList.txt"
$FilePath = "C:\Scripts\SCCM"
$smtpServers = "smtp1.domainname.com","smtp2.domainname.com"
$reliableSmtpServer = $null
$logpath = "C:\Scripts\SCCM\RequestLog.txt"

#logging functionality
function log($message, $type){
  $date = get-date
  $string = "$date $type : $message" | Out-File $logpath -Append
}

#does log exist?
if (gi -Path $logpath -ErrorAction SilentlyContinue){
  #yep, the log exists!
  $logContent = cat $logpath
  log -message "Script called and log opened for writing." -type "Info"
} else {
  #nope, the log doesn't exist, let's make one.
  write "Can't find log file, creating a new one."
  $newFileResult = New-Item -Path $logpath -ItemType File -ErrorAction Stop
  if ($newFileResult.Exists){
    log -message "new log file created" -type "Info"
  } #end if
} #end else

#Email variables
$from = "no.reply@domainname.com"
$to = "sccm-admin@domainname.com"
$subject = "New SCCM Application Approval Requests"

#Determine which SMTP to use.
$smtpServers | ForEach-Object {
  if ($reliableSmtpServer -eq $null){
    if (Test-Connection -ComputerName $_ -ErrorAction SilentlyContinue){
      write "Reliable SMTP server found: $_"
      $reliableSmtpServer = $_       
    } #end if test-connection
  } #end if reliableSmtpServer exists
} #end foreach SMTP server

if ($reliableSmtpServer){
  log -message "Reliable SMTP server found, $reliableSmtpServer" -type "Info"
} else {
  log -message "No reliable SMTP server could be found" -type "Error"
}

#Get the entries from GUIDList.txt
if ($GetGUID = Get-Content -Path $GUIDFilePath -ErrorVariable guidReadError {
  write "Successfully read $GUIDFilePath"
  log -message "Successfully read $GUIDFilePath" -type "Info"
} else {
  Write-Error -Message "Couldn't read GUIDfile..."
  log -message "Failed to read GUIDFile" -type "Error"
}

#Get all Application Requests with a CurrentState of "1"
log -message 'Attempting to get all Application Requests with a CurrentState of 1' -type "Info"
$GetAppRequest = Get-WmiObject -Class SMS_UserApplicationRequest -Namespace root/SMS/site_$SiteCode | Where-Object {$_.CurrentState -like "1"} | ForEach-Object {
  log -message "App found, $_.Application" -type "Info"
  if ($GetGUID -contains $_.RequestGuid) {
    Write-Host "Application request $($_.RequestGuid) already present"
    log -message "Application request $($_.RequestGuid) already present" -type "Info"
  } else {
    $appUser = $_.User
    $appName = $_.Application
    $appComment = $_.Comments
    $Body = @"
    Application request: $appName
    User: $appUser

    Comment: $appComment
    "@ #This row can't contain any blank spaces or tabs

    log -message "New record found: $appUser, $appName, $appComment" -type "Info"

   #Email configuration
    Send-MailMessage -SmtpServer $reliableSmtpServer -From $from -To $to -Subject $subject -Body $body -ErrorVariable mailError
   if (!($mailError)){
     write "Message successfully sent to : $to"
     log -message "Message successfully sent to : $to" -type "Info"
   } else {
     Write-Error -message "Failed to send email!"
     log -message "Failed to send email!" -type "Error"
   } #end else

   #Append the current objects GUID to GUIDList.txt
   Write "Appending $($_.RequestGUID) to $GUIDFilePath"
   log -message "Appending $($_.RequestGUID) to $GUIDFilePath" -type "Info"
$_.RequestGuid | Out-File $GUIDFilePath -Append

  } #end else statement
} #end forEach

#Remove the GUIDList.txt file and re-create it when there's more than 100 entries
$GUIDCount = $GetGUID.Count
if ($GUIDCount -gt 100) {
  log -message "Greater than 100 GUID entries, clearing list." -type "Info"
  Get-Item $GUIDFilePath | Remove-Item
  New-Item -Path $FilePath -Name GUIDList.txt -ItemType file
}

#Create a new log once the log file exceeds 1000 lines.
$logCount = $logContent.Count
if ($logCount -gt 1000) {
  log -message "Log file is too long, removing log" -type "Warning"
  Remove-Item $logpath
}

Here is the scheduled task XML:

<?xml version="1.0" encoding="UTF-16"?>
<Task version="1.3" xmlns="http://schemas.microsoft.com/windows/2004/02/mit/task">
  <RegistrationInfo>
    <Date>2014-05-09T17:10:48.6636926</Date>
    <Author>domainname\myUserAccount</Author>
    <Description>Runs a script located at C:\scripts\SCCM to determine if there are any new application requests and notify IT staff via Email.</Description>
  </RegistrationInfo>
  <Triggers>
    <TimeTrigger>
      <Repetition>
        <Interval>PT15M</Interval>
        <StopAtDurationEnd>false</StopAtDurationEnd>
      </Repetition>
      <StartBoundary>2014-05-09T17:12:04</StartBoundary>
      <ExecutionTimeLimit>PT1H</ExecutionTimeLimit>
      <Enabled>true</Enabled>
    </TimeTrigger>
  </Triggers>
  <Principals>
    <Principal id="Author">
      <UserId>domain\AdminAccount</UserId>
      <LogonType>Password</LogonType>
      <RunLevel>HighestAvailable</RunLevel>
    </Principal>
  </Principals>
  <Settings>
    <MultipleInstancesPolicy>IgnoreNew</MultipleInstancesPolicy>
    <DisallowStartIfOnBatteries>true</DisallowStartIfOnBatteries>
    <StopIfGoingOnBatteries>true</StopIfGoingOnBatteries>
    <AllowHardTerminate>true</AllowHardTerminate>
    <StartWhenAvailable>false</StartWhenAvailable>
    <RunOnlyIfNetworkAvailable>false</RunOnlyIfNetworkAvailable>
    <IdleSettings>
      <StopOnIdleEnd>true</StopOnIdleEnd>
      <RestartOnIdle>false</RestartOnIdle>
    </IdleSettings>
    <AllowStartOnDemand>true</AllowStartOnDemand>
    <Enabled>true</Enabled>
    <Hidden>false</Hidden>
    <RunOnlyIfIdle>false</RunOnlyIfIdle>
    <DisallowStartOnRemoteAppSession>false</DisallowStartOnRemoteAppSession>
    <UseUnifiedSchedulingEngine>false</UseUnifiedSchedulingEngine>
    <WakeToRun>false</WakeToRun>
    <ExecutionTimeLimit>P3D</ExecutionTimeLimit>
    <Priority>7</Priority>
  </Settings>
  <Actions Context="Author">
    <Exec>
      <Command>powershell.exe</Command>
      <Arguments>-noprofile -file "C:\scripts\sccm\Notify.ps1"</Arguments>
    </Exec>
  </Actions>
</Task>

Answer 1

Did you mean to assign the results of the Get-WmiObject ... | Foreach-Object { line to the $GetAppRequest variable? What I mean is that the output of the Foreach-Object loop are being caught by that assignment which doesn't look intentional since you don't use that variable again.

I'd suggest that you perform the assignment to the variable then pass the variable to the Foreach-Object cmdlet separately with some logging in between. Also, we could wrap the Get-WmiObject in a try{}catch{} construction to capture any errors the cmdlet might throw; to ensure the error is caught, we set -ErrorAction Stop:

try {
  $GetAppRequest = Get-WmiObject -Class SMS_UserApplicationRequest -Namespace root/SMS/site_$SiteCode -ErrorAction Stop
}
catch {
  log -message "Get-WmiObject cmdlet failed" -type "Error"
  log -message $_.Exception.Message.ToString() -type "Error"
}

if(-not $GetAppRequest) {
  log -message "Failed to retrieve WMI data" -type "Error"

} elseif(-not ($GetAppRequest = $GetAppRequest | Where-Object {$_.CurrentState -like "1"})) {
  log -message "No results with CurrentState = 1" -type "Info"
}

$GetAppRequest | ForEach-Object {
  ...

Answer 2

Check with "run only when the user is logged on" and hidden checkbox unchecked.