Unable to connect to Windows Admin Center on Azure VM (Error: Not authorized / JSON File Not Found)

Question

Cannot access my Azure VM via remote control. These are the following errors can you please help me how to solve it even i couldnt solve it via Google Gemini Unable to connect to Windows Admin Center on Azure VM (Error: Not authorized / JSON File Not Found)

Problem Description:

I am experiencing a persistent "Not authorized" error when attempting to connect to my Azure VM via Windows Admin Center (WAC), despite having all prerequisites configured.

Environment Details:

VM Name: penlyeng

OS: Windows Server

Accessing from: macOS (Microsoft Remote Desktop / Browser)

Troubleshooting Steps Taken:

Network Security Group (Inbound): I have manually added an inbound rule for port 6516 for my specific source The Azure portal confirms VM access is "Configured."

Network Security Group (Outbound): I have manually added outbound rules for port 443 using the WindowsAdminCenter and AzureCloud service tags.

RBAC Permissions: I have assigned the "Windows Admin Center Administrator Login" role to my user account. When I attempt to re-add the role, the portal confirms the assignment already exists (ID:

Guest Account Status: My account is a Guest in this tenant (adminpenly advice(Guest)), but the role assignment is confirmed at the VM scope.

Account Lockout: I have performed a Password Reset via the portal to ensure the user account is not locked (Error 0xd07 was previously observed but cleared).

Current Errors:

Portal UI: Shows "You are not authorized to access this site" even after logging out and back in.

Previous JSON Error: Intermittently received {"error":{"message":"File not found","code":"NotFound"}} when the WAC blade attempts to load.

Requested Assistance:

Please verify why the WindowsAdminCenter extension is failing to recognize the existing RBAC role assignment and why the outbound port rule check continues to fail intermittently despite the manual NSG rule being present.

Answer 1

Hello Farhad Waizi,

Thank you for reaching out and for sharing the detailed information and screenshots related to the issue you are experiencing while connecting to Windows Admin Center (WAC) on your Azure virtual machine.

From the details provided, we understand that you are encountering a “You are not authorized to access this site” error even though the required role assignment and network configurations appear to be in place.

Based on the investigation and observed behavior, this issue is not related to missing NSG rules or an incorrect role configuration. The Windows Admin Center Administrator Login role has already been assigned correctly at the virtual machine resource scope, and the duplicate assignment message confirms that RBAC is functioning as expected.

The behavior you are encountering aligns with a known limitation in how Windows Admin Center handles identity authorization and extension validation in Azure. Specifically, when Windows Admin Center is accessed using a Guest (external) Microsoft Entra ID account, the extension may fail during token validation even though RBAC permissions are correctly configured. This can result in errors such as:

• “You are not authorized to access this site”
• Intermittent “File not found (NotFound)” or JSON load errors in the WAC blade

Additionally, the “Failed to configure outbound port rule” message observed in the Azure portal is a known portal-side validation behavior. This message does not necessarily indicate a real network connectivity issue and can appear even when outbound HTTPS (port 443) access is already allowed through existing NSG rules or default Azure networking configurations

To resolve this issue, we recommend using a member (non-Guest) Microsoft Entra ID account, as this is the supported and more reliable approach for Windows Admin Center access. Please update the user type from Guest to Member in Microsoft Entra ID (this action requires appropriate administrative permissions), allow time for the change to propagate, and then sign out of all active sessions before attempting to reconnect from the Azure portal.

Reference:

Manage a Windows VM using Windows Admin Center in Azure

Windows Admin Center known issues

Hope this helps! Please let me know if you have any queries in comments.