While updating image reference, portal shows “No existing galleries in subscription"

Anil Mekala (INFOSYS LIMITED) 0 Reputation points Microsoft External Staff
2026-05-25T00:55:52.06+00:00

We are trying to migrate a VMSS from EOL .NET 6 (WS2022 Marketplace image) as part of Project Standard ST0002 compliance

While changing image reference (VMSS → Operating system → Change image reference), Azure Compute Gallery shows “No existing galleries in subscription”.

Onboard this subscription to 1P Image Gallery (Azure Compute Gallery)

Azure Virtual Machine Scale Sets
Azure Virtual Machine Scale Sets

Azure compute resources that are used to create and manage groups of heterogeneous load-balanced virtual machines.


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  1. Nikhil Duserla 9,950 Reputation points Microsoft External Staff Moderator
    2026-06-01T09:48:12.6066667+00:00

    Hey Anil, it looks like the portal is telling you that your subscription doesn’t yet see any Azure Compute Galleries (SIGs), so you can’t pick an image from one. Here’s how to get “onboarded” so that the ST0002 1P gallery (or any gallery) shows up in your subscription:

    1. Register the Compute resource provider • In the Azure portal go to Subscriptions → your subscription → Resource providers • Find “Microsoft.Compute” and click Register • Wait a minute for the status to switch to Registered
    2. If you already have a central ST0002 gallery in another subscription a. In the gallery-owning subscription, open the Shared Image Gallery (Project ST0002) b. Under Access control (IAM) or the Sharing blade, click + Add → Share with subscriptions c. Enter your target subscription ID, grant at least the Reader role, and save d. Now switch back to your subscription and retry the VMSS image‐change flow: VMSS → Operating system → Change image reference → My Shared Images
    3. If you don’t yet have a gallery in this subscription (you want your own) • Search for “Shared Image Galleries” in the portal, click + Add • Fill in Name, Resource Group, regions, etc., then Review + Create • Populate your image definitions/versions, replicate to needed regions • Retry VMSS → Change image reference after the gallery is up
    4. Double-check your permissions • In your subscription’s IAM, verify you (and the VMSS operator) have at least Reader on the SIG resource (or its resource group)

    If you go through these steps and still see “No existing galleries,” can you share:

    • Do you already have the ST0002 gallery in another subscription or management group?
    • Were you granted Reader on that gallery?
    • Have you confirmed Microsoft.Compute is Registered in your subscription?

    References you can include in your forum response:

    Hope that helps! Let me know how it goes or if any of those steps throws an error.

    Note: This content was drafted with the help of an AI system. Please verify the information before relying on it for decision-making.

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