Resolving DownloadString Error in Azure DevOps Pipelines

May 05, 2025     1 minute read

On May 1st, we encountered a new error in our Azure DevOps pipelines. The error occurred while using PowerShell scripts to download the bccontainerhelper. This blog post will detail the issue, the investigation process, and the solution to resolve the error.

Issue Description

Our pipelines started throwing a DownloadString error when attempting to download the bccontainerhelper. This error was unexpected and disrupted our workflow. Upon investigation, we discovered that the issue was due to changes in the bccontainerhelper module, specifically starting from version 6.1.

You can see an issue logged in Github related to this

https://github.com/microsoft/navcontainerhelper/issues/3903

You may encounter this error while creating container or when you use Get-BCArtifact

Error querying artifacts. Error message was The remote server returned an error: (404) Not Found.

Solution

To fix the error you just need to update your bccontainerhelper module using the below commond

Update-Module bccontainerhelper -force

The above update will resolve the issue for some users but some of use who are using old powershell scripts in Azure DevOps pipelines you need to update the script in Install-BCContainerHelper.ps1, I have added the script in the above Github issue but you can also copy the below script and replace it

Param(
    [string] $bcContainerHelperVersion = "",
    [string] $genericImageName = ""
)

if ($bcContainerHelperVersion -eq "") { $bcContainerHelperVersion = "latest" }
if ($bccontainerHelperVersion -eq "dev") { $bccontainerHelperVersion = "https://github.com/microsoft/navcontainerhelper/archive/dev.zip" }

if ($bccontainerHelperVersion -like "https://*") {
    $path = Join-Path $env:TEMP ([Guid]::NewGuid().ToString())
}
else {
    $bcbaseurl = "https://bccontainerhelper.blob.core.windows.net/public"
    

    
    $latestVersion = "latest"
    $previewVersion = "preview"
    if ($bccontainerHelperVersion -eq "latest") {
        $bccontainerHelperVersion = $latestVersion
    }
    elseif ($bccontainerHelperVersion -eq "preview") {
        $bccontainerHelperVersion = $previewVersion
    }
    $basePath = Join-Path $env:ProgramFiles "WindowsPowerShell\Modules\BcContainerHelper"
    if (!(Test-Path $basePath)) { New-Item $basePath -ItemType Directory | Out-Null }
    $path = Join-Path $basePath $bccontainerHelperVersion
    $bccontainerHelperVersion = "$bcbaseurl/$bccontainerHelperVersion.zip"
}

$bchMutexName = "bcContainerHelper"
$bchMutex = New-Object System.Threading.Mutex($false, $bchMutexName)
try {
    try { $bchMutex.WaitOne() | Out-Null } catch {}
    if (!(Test-Path $path)) {
        $tempName = Join-Path $env:TEMP ([Guid]::NewGuid().ToString())
        Write-Host "Downloading $bccontainerHelperVersion"
        (New-Object System.Net.WebClient).DownloadFile($bccontainerHelperVersion, "$tempName.zip")
        Expand-Archive -Path "$tempName.zip" -DestinationPath $tempName
        $folder = (Get-Item -Path (Join-Path $tempName '*')).FullName
        [System.IO.Directory]::Move($folder,$path)
    }
}
finally {
    $bchMutex.ReleaseMutex()
}
. (Join-Path $path "BcContainerHelper.ps1")

if ($genericImageName) {
    $bcContainerHelperConfig.genericImageName = $genericImageName
}

By following the steps outlined above, you can resolve the DownloadString error in your Azure DevOps pipelines. Keeping your modules and scripts up-to-date is essential to maintaining a smooth and error-free workflow.

For more details about the update or issue check Github Issue.