PowerShell script does not finish when started from Task Scheduler

Question

I have a PowerShell script from here:

https://github.com/Azure/azure-devtestlab/blob/master/Artifacts/windows-vsts-download-and-run-script/DownloadVstsDropAndExecuteScript.ps1

that I use to download VSTS build artifacts:

[CmdletBinding()]
param(
    [string] $accessToken,
    [string] $buildDefinitionName,
    [string] $vstsProjectUri,
    [string] $pathToScript,
    [string] $scriptArguments,
    [string] $buildDefId
)

###################################################################################################
#
# PowerShell configurations
#

# NOTE: Because the $ErrorActionPreference is "Stop", this script will stop on first failure.
#       This is necessary to ensure we capture errors inside the try-catch-finally block.
$ErrorActionPreference = "Stop"

# Ensure we force use of TLS 1.2 for all downloads.
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12

# Ensure we set the working directory to that of the script.
Push-Location $PSScriptRoot

# Configure strict debugging.
Set-PSDebug -Strict

###################################################################################################
#
# Handle all errors in this script.
#

trap
{
    # NOTE: This trap will handle all errors. There should be no need to use a catch below in this
    #       script, unless you want to ignore a specific error.
    $message = $error[0].Exception.Message
    if ($message)
    {
        Write-Host -Object "ERROR: $message" -ForegroundColor Red
    }
    
    # IMPORTANT NOTE: Throwing a terminating error (using $ErrorActionPreference = "Stop") still
    # returns exit code zero from the PowerShell script when using -File. The workaround is to
    # NOT use -File when calling this script and leverage the try-catch-finally block and return
    # a non-zero exit code from the catch block.
    exit -1
}

###################################################################################################
#
# Functions used in this script.
#

function Get-BuildArtifacts
{
    [CmdletBinding()]
    param (
        [string] $ArtifactsUri,
        [Hashtable] $Headers,
        [string] $Destination
    )

    # Clean up destination path first, if needed.
    if (Test-Path $Destination -PathType Container)
    {
        Write-Host "Cleaning up destination folder $Destination"
        Remove-Item -Path $Destination -Force -Recurse | Out-Null
    }

    Write-Host "Getting build artifacts information from $ArtifactsUri"
    [Array] $artifacts = (Invoke-RestMethod -Uri $ArtifactsUri -Headers $Headers -Method Get | ConvertTo-Json -Depth 3 | ConvertFrom-Json).value

    # Process all artifacts found.
    foreach ($artifact in $artifacts)
    {
        if ($artifact.resource.type -notlike "Container") {
            Write-Host "Skip download of artifact $($artifact.name) as it is not of type 'Container'"
            continue
        }
        
        $artifactName = "$($artifact.name)"
        $artifactZip = "$artifactName.zip"
        Write-Host "Preparing to download artifact $artifactName to file $artifactZip"

        $downloadUrl = $artifact.resource.downloadUrl
        if (-not $downloadUrl)
        {
            throw "Unable to get the download URL for artifact $artifactName."
        }

        $outfile = "$PSScriptRoot\$artifactZip"

        Write-Host "Downloading artifact $artifactName from $downloadUrl"
        Invoke-RestMethod -Uri "$downloadUrl" -Headers $Headers -Method Get -Outfile $outfile | Out-Null

        Write-Host "Extracting artifact file $artifactZip to $Destination"
        [System.Reflection.Assembly]::LoadWithPartialName("System.IO.Compression.FileSystem") | Out-Null 
        [System.IO.Compression.ZipFile]::ExtractToDirectory($outfile, $Destination) | Out-Null
    }
}

function Get-BuildDefinitionId
{
    [CmdletBinding()]
    param (
        [string] $BuildDefinitionUri,
        [Hashtable] $Headers
    )

    Write-Host "Getting build definition ID from $BuildDefinitionUri"
    $buildDef = Invoke-RestMethod -Uri $BuildDefinitionUri -Headers $Headers -Method Get
    if (-not $buildDefId)
    {
     $buildDefinitionId = $buildDef.value.id[0]
     if (-not $buildDefinitionId)
      {
          throw "Unable to get the build definition ID from $buildDefinitionUri"
      }
    }
    else
    {
        $buildDefinitionId = $buildDefId
    }
    
   

    return $buildDefinitionId
}

function Get-LatestBuildId
{
    param (
        [string] $BuildUri,
        [Hashtable] $Headers
    )

    Write-Host "Getting latest build ID from $BuildUri"
    $builds = Invoke-RestMethod -Uri $BuildUri -Headers $Headers -Method Get | ConvertTo-Json | ConvertFrom-Json
    $buildId = $builds.value[0].id
    if (-not $buildId)
    {
        throw "Unable to get the latest build ID from $BuildUri"
    }

    return $buildId
}
 
function Invoke-Script
{
    [CmdletBinding()]
    param (
        [string] $Path,
        [string] $Script,
        [string] $Arguments
    )

    $scriptPath = Join-Path -Path $Path -ChildPath $Script

    Write-Host "Running $scriptPath"

    if (Test-Path $scriptPath -PathType Leaf)
    {
        Invoke-Expression "& `"$scriptPath`" $Arguments"
    }
    else
    {
        Write-Error "Unable to locate $scriptPath"
    }
}

function Set-AuthHeaders
{
    [CmdletBinding()]
    param (
        [string] $UserName = "",
        [string] $AccessToken
    )

    $basicAuth = [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(("{0}:{1}" -f $UserName,$AccessToken)))
    return @{ Authorization = "Basic $basicAuth" }
}

###################################################################################################
#
# Main execution block.
#

try
{
    # Prepare values used throughout.
    $vstsApiVersion = "2.0"
    $destination = "$($env:HOMEDRIVE)\$buildDefinitionName"
    $vstsProjectUri = $vstsProjectUri.TrimEnd("/")
    $headers = Set-AuthHeaders -AccessToken $accessToken

    # Output provided parameters.
    Write-Host 'Provided parameters used in this script:'
    Write-Host "  `$accessToken = $('*' * $accessToken.Length)"
    Write-Host "  `$buildDefinitionName = $buildDefinitionName"
    Write-Host "  `$vstsProjectUri = $vstsProjectUri"
    Write-Host "  `$pathToScript = $pathToScript"
    Write-Host "  `$scriptArguments = $scriptArguments"

    # Output constructed variables.
    Write-Host 'Variables used in this script:'
    Write-Host "  `$vstsApiVersion = $vstsApiVersion"
    Write-Host "  `$outfile = $outfile"
    Write-Host "  `$destination = $destination"

    # Get the build definition ID.
    $buildDefinitionUri = "$vstsProjectUri/_apis/build/definitions?api-version=$vstsApiVersion&name=$buildDefinitionName"
    $buildDefinitionId = Get-BuildDefinitionId -BuildDefinitionUri $buildDefinitionUri -Headers $headers

    # Get the ID of the latest successful build.
    $buildUri = "$vstsProjectUri/_apis/build/builds/?api-version=$vstsApiVersion&definitions=$buildDefinitionId&statusFilter=succeeded";
    $buildId = Get-LatestBuildId -BuildUri $buildUri -Headers $headers

    # Download the build artifact package.
    $artifactsUri = "$vstsProjectUri/_apis/build/builds/$buildId/Artifacts?api-version=$vstsApiVersion";
    Get-BuildArtifacts -ArtifactsUri $artifactsUri -Headers $headers -Destination $destination

    # Run the script specified after having successfully downloaded the build artifact package.
    Invoke-Script -Path $destination -Script $pathToScript -Arguments $scriptArguments
}
finally
{
    Pop-Location
}

The script works perfectly when I run it in PowerShell. It works flawlessly when I run it from Command Prompt like this:

powershell.exe -ExecutionPolicy Bypass C:\PathToScript\DownloadVstsDropAndExecuteScript.ps1 -parameters

However when I try to run it as a scheduled task the script does not seem to finish the download (zip file size is to small and when I try to open, the file is corrupt). Both in user-logged-on-mode and without logged-in user.

The task xml is here:

<?xml version="1.0" encoding="UTF-16"?>
<Task version="1.2"     xmlns="http://schemas.microsoft.com/windows/2004/02/mit/task">
  <RegistrationInfo>
    <Date>2018-07-17T08:39:31.2909587</Date>
    <Author>LOCALPC\Administrator</Author>
    <URI>\Download Nightly Artifacts</URI>
  </RegistrationInfo>
  <Triggers>
    <CalendarTrigger>
      <StartBoundary>2018-07-17T04:44:44</StartBoundary>
      <ExecutionTimeLimit>PT2H</ExecutionTimeLimit>
      <Enabled>true</Enabled>
      <ScheduleByWeek>
        <DaysOfWeek>
          <Monday />
          <Tuesday />
          <Wednesday />
          <Thursday />
          <Friday />
          <Saturday />
        </DaysOfWeek>
        <WeeksInterval>1</WeeksInterval>
      </ScheduleByWeek>
    </CalendarTrigger>
   </Triggers>
  <Principals>
     <Principal id="Author">
       <UserId>S-1-5-21-1204101111-744349012-1702229681-300</UserId>
       <LogonType>InteractiveToken</LogonType>
      <RunLevel>HighestAvailable</RunLevel>
     </Principal>
  </Principals>
  <Settings>
    <MultipleInstancesPolicy>IgnoreNew</MultipleInstancesPolicy>
    <DisallowStartIfOnBatteries>false</DisallowStartIfOnBatteries>
    <StopIfGoingOnBatteries>false</StopIfGoingOnBatteries>
    <AllowHardTerminate>true</AllowHardTerminate>
    <StartWhenAvailable>true</StartWhenAvailable>
    <RunOnlyIfNetworkAvailable>false</RunOnlyIfNetworkAvailable>
    <IdleSettings>
      <StopOnIdleEnd>true</StopOnIdleEnd>
      <RestartOnIdle>false</RestartOnIdle>
    </IdleSettings>
    <AllowStartOnDemand>true</AllowStartOnDemand>
    <Enabled>true</Enabled>
    <Hidden>false</Hidden>
    <RunOnlyIfIdle>false</RunOnlyIfIdle>
    <WakeToRun>true</WakeToRun>
    <ExecutionTimeLimit>PT2H</ExecutionTimeLimit>
    <Priority>7</Priority>
  </Settings>
  <Actions Context="Author">
    <Exec>
      <Command>powershell.exe</Command>
      <Arguments>C:\PathToScript\DownloadVstsDropAndExecuteScript.ps1 -parameters</Arguments>
    </Exec>
  </Actions>
</Task>

Answer 1

Replaced

Invoke-RestMethod -Uri "$downloadUrl" -Headers $Headers -Method Get -Outfile $outfile | Out-Null

with

$wc = New-Object System.Net.WebClient
    foreach ($key in $Headers.Keys) {
        $wc.Headers.Add($key, $Headers[$key])
    }
    $wc.DownloadFile($downloadUrl, $outfile)

Thanks to @anheledir for the solution