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vmCreation-linkedTemplate-0d336b8c-e524-420a-b054-ff46deba6311 | Overview - AVD pool creation time

Selvakumar Balakrishnan 0 Reputation points
2026-05-06T21:25:51.71+00:00

VM has reported a failure when processing extension 'Microsoft.PowerShell.DSC' (publisher 'Microsoft.Powershell' and type 'DSC'). Error message: 'The DSC Extension failed to execute: Error downloading https://wvdportalstorageblob.blob.core.windows.net/galleryartifacts/Configuration_1.0.03391.1266.zip after 17 attempts: Unable to connect to the remote server. More information about the failure can be found in the logs located under 'C:\WindowsAzure\Logs\Plugins\Microsoft.Powershell.DSC\2.83.5' on the VM.'. More information on troubleshooting is available at https://aka.ms/VMExtensionDSCWindowsTroubleshoot (Code: VMExtensionProvisioningError)

i am getting this message while creating AVD pool. Any luck?

Azure Virtual Desktop
Azure Virtual Desktop

A Microsoft desktop and app virtualization service that runs on Azure. Previously known as Windows Virtual Desktop.

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  1. Manish Deshpande 6,340 Reputation points Microsoft External Staff Moderator
    2026-05-07T00:41:36.2733333+00:00

    Hello @Selvakumar Balakrishnan

    Thanks for posting this. The error you're seeing means the DSC extension on the session host VM couldn't download the configuration package from Azure's gallery storage endpoint during provisioning. This is almost always a network connectivity issue rather than a problem with your AVD configuration itself.

    Here's what I'd recommend you checking:

    1. NSG / Firewall Rules

    The VM needs outbound HTTPS (port 443) access to several Microsoft endpoints during provisioning. Make sure none of your NSGs, Azure Firewall, or UDRs are blocking traffic to:

    • blob.core.windows.net (for gallery artifacts)
    • wvd.microsoft.com
    • servicebus.windows.net

    → Required URL link: https://learn.microsoft.com/en-us/azure/virtual-desktop/safe-url-list

    1. DNS Resolution

    If you're using a custom DNS server, verify the VM can resolve wvdportalstorageblob.blob.core.windows.net. You can test this by deploying a small test VM in the same subnet and running nslookup or Resolve-DnsName against that hostname.

    1. Private Endpoint / Service Endpoint conflicts

    If your storage accounts use private endpoints, the VM may be trying to reach a public endpoint that's being blocked by policy. Check whether any Azure Policy or private DNS zone is intercepting blob.core.windows.net resolution unexpectedly.

    1. Proxy configuration

    If outbound internet goes through a proxy, the VM won't automatically use it during the DSC phase unless configured. Check if a proxy is required in your environment and configure it via WinHTTP:

    netsh winhttp set proxy <proxy-server>:<port>

    1. Retry / Re-run the deployment

    Occasionally this can be a transient throttling issue on the storage side. After verifying the above, simply delete the host pool and redeploy — the DSC extension doesn't cleanly recover from a mid-provisioning failure.

    Links:
    https://learn.microsoft.com/en-us/azure/virtual-machines/extensions/dsc-troubleshoot
    https://learn.microsoft.com/en-us/azure/virtual-desktop/safe-url-list
    https://learn.microsoft.com/en-us/azure/virtual-desktop/troubleshoot-set-up-issues
    https://learn.microsoft.com/en-us/azure/virtual-desktop/proxy-server-support

    Hope this gets you unblocked!

    Thanks,
    Manish.

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  2. AI answer

    2026-05-06T21:26:04.3533333+00:00

    The error indicates that the PowerShell DSC extension on the session host VM cannot download the configuration ZIP from the specified URL after multiple attempts. This is treated as a VMExtensionProvisioningError during AVD host pool creation.

    In this scenario, the DSC extension is required for AVD session host configuration (for example, the FirstSessionHost configuration). When it cannot reach the configuration package, the extension fails and the deployment reports a failure.

    Based on the provided context, this falls under the category of “VM has reported a failure when processing extension” and “DeploymentFailed – PowerShell DSC Configuration 'FirstSessionHost' completed with errors” during AVD host pool creation.

    To resolve:

    1. Verify network connectivity from the VM to the required Azure endpoints
      • The error Unable to connect to the remote server strongly suggests a connectivity or outbound access issue from the VM to the storage endpoint hosting the configuration ZIP.
      • Ensure that outbound internet access or required service endpoints are allowed from the subnet where the session host VMs are deployed.
      • Check any NSGs, firewalls, or proxies that might be blocking outbound HTTPS traffic.
    2. Confirm the DSC extension can run with admin privileges
      • For AVD, a common cause of DSC-related deployment failures is that the extension cannot obtain admin access on the VM.
      • Confirm that the username and password specified in the ARM template for the session host have local administrator rights on the VM, then rerun the template.
    3. Check the DSC extension logs on the VM
      • Connect to the VM (if possible) and review the extension logs and status files:
        • Status file: C:\Packages\Plugins\Microsoft.Powershell.DSC\<Extension_Version>\Status\{0}.Status
        • Logs: C:\WindowsAzure\Logs\Plugins\Microsoft.Powershell.DSC\<Extension_Version>
      • These logs contain detailed error messages and substatus codes that can confirm whether the failure is purely connectivity-related or also permission-related.
    4. Re-run the host pool deployment after fixing connectivity
      • Once outbound connectivity and admin access are confirmed, re-run the AVD host pool ARM template deployment.

    If the error persists after confirming outbound access and admin rights, use the DSC and VM extension troubleshooting guidance to further inspect DSC logs (Microsoft-Windows-Dsc/Operational) and extension status, then reattempt the deployment.

    References:

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