Windows Development

The HTTP 401 Unauthorized response indicates that the request has not been applied because it lacks valid authentication credentials for the target resource. In your case, the error message specifies that the provided access token is either invalid or has expired. Here are the key points from the response:

1. AuthenticationError: This indicates a failure in the authentication process.
2. InvalidCredentials: The access token signature is invalid, suggesting that the token you are using may not be correctly signed or is not recognized by the server.
3. TokenExpired: The access token has expired, meaning you need to acquire a new token from the Microsoft Identity Platform.
4. AuthPolicyViolation: Your client application may not have the necessary permissions for the requested resource scope.

To resolve this issue, you should:

• Ensure that you are using a valid OAuth 2.0 token.
• Acquire a new access token if the current one has expired.
• Check the permissions of your client application to ensure it is authorized for the resource you are trying to access.

"code": "AuthenticationError",

"message": "Authentication failed. The provided access token is invalid or has expired.",

"target": "AuthorizationHeader",

"innerError": {

"date": "2025-10-28T14:42:00Z",

"request-id": "5fbc7a22-a1d3-47c9-b91a-18883518503",

"client-request-id": "18883518503"

},

"details": [

{

"code": "InvalidCredentials",

"message": "Access token signature is invalid. Please ensure you are using a valid OAuth 2.0 token."

},

{

"code": "TokenExpired",

"message": "The access token expired at 2025-10-28T13:30:00Z. Acquire a new token from Microsoft Identity Platform."

},

{

"code": "AuthPolicyViolation",

"message": "Your client application is not authorized for the requested resource scope."

}

]